MERCOR MINI-PT, -P, -T CORRECTORS MINI-PT, -P, -T. User Guide V July 2008

Transcription

1 MINI-PT, -P, -T User Guide V 1.01 July 2008 P Virginia Avenue, Cincinnati, OH USA F Page 1

2 COPYRIGHT NOTICE MERCOR MINI-PT, -P, -T ELECTRONIC VOLUME CORRECTORS USERS MANUAL COPYRIGHT (C) 2008 by Mercury Instruments. All Rights Reserved. Page 2 This manual covers firmware versions 1.30, 1.40 and version 1.50 Revision Date: November 30, 1997

3 CONTENTS SECTION DESCRIPTION PAGE INTRODUCTION WARRANTY INTRINSIC SAFETY CORRECTION FACTORS TO METERED VOLUME PRESSURE FACTOR, Fp TEMPERATURE FACTOR, Ft SUPERCOMPRESSIBILITY FACTOR, Fpv HOW THE MERCOR MINI WORKS DRIVE INPUT PRESSURE SYSTEM TEMPERATURE SYSTEM SUPERCOMPRESSIBILITY CORRECTION INFORMATION DISPLAY COMPUTATION INTERVAL ACCESS LEVELS FOR OPERATING PERSONNEL POWER SUPPLY INSTALL & OPERATE THE MERCOR MINI RECEIVING FUNCTION CHECK PRESSURE FUNCTION CHECK - GAUGE Page 3

4 CONTENTS SECTION DESCRIPTION PAGE PRESSURE FUNCTION CHECK - ABSOLUTE TEMPERATURE FUNCTION CHECK VOLUME FUNCTION CHECK BATTERY PACK CHECK CHANGING BATTERIES BATTERY SHUTDOWN - HELP DISPLAY PULSE OUTPUT TERMINAL CONNECTIONS INSTRUMENT MOUNTING CHECK ROTATION MERCOR MINI OPERATING MODES CORRECTOR MODE METER READER MODE LEVEL 1 ACCESS MODE LEVEL 2 ACCESS MODE SERIAL MODE METER READER MODE OPERATION GAINING ACCESS TO METER READER MODE DEFAULT METER READER DISPLAY ENHANCED METER READER DISPLAY MAG LIST Page 4

5 CONTENTS SECTION DESCRIPTION PAGE LIVE PARAMETERS DISPLAY MAG LIST ITEM NUMBER ENABLE INSTRUMENT CALIBRATION POINT PRESSURE CALIBRATION (Defined) POINT PRESSURE CALIBRATION (Gauge Transducers) POINT PRESSURE CALIBRATION (Items Required) POINT PRESSURE CALIBRATION (Procedure-Gauge) POINT PRESSURE CALIBRATION (Absolute-Transducers) POINT PRESSURE CALIBRATION (Items Required) POINT PRESSURE CALIBRATION (Procedure-Absolute) SINGLE-POINT PRESSURE CALIBRATION SINGLE-POINT PRESSURE CALIBRATION (Defined) SINGLE-POINT PRESSURE CALIBRATION (Items Required) SINGLE-POINT PRESSURE CALIBRATION (Procedure) POINT TEMPERATURE CALIBRATION (Defined) POINT TEMPERATURE CALIBRATION POINT TEMPERATURE CALIBRATION (Items Required) POINT TEMPERATURE CALIBRATION (Procedure) SINGLE-POINT TEMPERATURE CALIBRATION Page 5

6 CONTENTS SECTION DESCRIPTION PAGE SINGLE-POINT TEMPERATURE CALIBRATION (Defined) SINGLE-POINT TEMPERATURE CALIBRATION (Items Req) SINGLE-POINT TEMPERATURE CALIBRATION (Procedure) ITEM CODE LIST (Definitions) PULSE OUTPUT UNCORRECTED VOLUME PULSES CORRECTED VOLUME PULSES CORRECTED VOLUME PULSES (FORM-A) CORRECTED VOLUME PULSES (FORM-C) ALARM PULSES (FORM-A) OUTPUT PULSE SPECIFICATIONS OPERATING SPECIFICATIONS DESIGN SPECIFICATIONS COMPLIANCE INFORMATION DRAWINGS INDEX Page 6

7 1.0 INTRODUCTION The Mercor Mini is a microprocessor-based, stand-alone, self-powered, meter-mounted instrument which provides a corrected volume reading on any gas meter having a rotating shaft output. It converts displaced volume to standard volume referenced to a pressure and a temperature base, and also applies supercompressibility correction. The Mercor Mini can be used on diaphragm, rotary or turbine gas meters. The universal mounting bracket includes a standard index for indicating uncorrected gas volume. The Mercor Mini is available as a pressure only (Mini-P), temperature only (Mini-T) or with pressure and temperature (Mini-PT). The supercompressibility capability is included in all three versions and may be configured as a dynamic calculation or as a fixed-factor. The companion software package, Mini-Link is required to configure and calibrate all versions of Mercor Minis. The easy-to-use program with pull-down menus allows each instrument to be configured for: Volume, Pressure, Temperature, Supercompressibility, English or Metric units of measure, Meter index, Base conditions, Scaling factors, Alarms and Alarm limits. Refer to the Mini-Link User's Guide for additional information on these and other functions YEAR WARRANTY warrants all instruments covered by this manual to be free from defects in material and workmanship under normal use and service. The Company agrees to repair or replace any instrument which its examination reveals to have been defective, due to faulty workmanship or material and if returned to our factory, transportation charges prepaid, within 2 years of purchase date. This warranty is in lieu of all other warranties, express or implied. All obligations or liabilities on the Company s part for damages, including but not limited to consequential damages, following the use or misuse of instruments sold by it. No agent is authorized to assume for it any liability except as set forth above. Information in this manual is correct as of the date of publication. The Company reserves the right to make design or material changes without notice, and without obligation to make similar changes on equipment of prior manufacture. 3.0 INTRINSIC SAFETY FOR HAZARDOUS LOCATIONS The Mercor Mini is listed as intrinsically safe by Underwriter s Laboratories (UL) for use in Class I, Division 1, Group D hazardous locations, and by Canadian Standards Associations (CSA) for use in Class I, Division 1, Groups C & D hazardous locations. The Mercor Mini is recognized as intrinsically safe when installed in accordance with (UL) control drawing or (CSA) control drawing , see pages 69 & 70 of this instruction manual. Warning: Substitution of components may impair intrinsic safety. Page 7

8 4.0 CORRECTION FACTORS TO METERED VOLUME Ideal or perfect gases follow the relationship of Boyle s Law for pressure effect and Charles Law for temperature effect, which can be stated: The volume of any definite weight of a perfect gas varies inversely with change in absolute pressure and directly with change in absolute temperature. The equation for this relationship of the two laws is expressed as follows: V1 P1 T1 = V2 P2 T2 The Symbols V1, P1 and T1 refer to the original volume, pressure and temperature while V2, P2 and T2 refer to the volume, pressure and temperature of the new or changed conditions. Rearranging the equation and rewriting subscripts, we can express it as follows: Vb = Vm x Pm Pb x Tb Tm Where: Vb Pb Tb Vm Pm Tm = gas volume (cu. ft.) at base condition corrected = absolute base pressure (psia) = absolute base temperature (deg. R) = gas volume metered (cu. ft.) uncorrected = absolute meter pressure (psia) = absolute meter temperature (deg. R) 4.1 Pressure Factor Fp The pressure factor (Fp) to apply to metered volume is expressed by the Boyle s Law relationship as follows: Pm Fp = = Pb Meter pressure (PSIG) + atmospheric pressure (PSIA) Base pressure (PSIA) Each increment of meter pressure represents a different pressure factor. As the flowing gas pressure (Pm) changes, the Mercor Mini automatically applies the pressure factor (Fp) to the metered volume (Vm). Page 8

9 4.2 Temperature Factor Ft The temperature factor (Ft) to apply to metered volume is expressed by the Charles Law relationship as follows: Tb Base temperature, deg. F Ft = = Tm Meter temperature, deg. F Each increment of meter temperature represents a different temperature factor. Therefore, as the flowing gas temperature (Tm) changes, the Mercor Mini automatically applies the temperature factor (Ft) to the metered volume. 4.3 Supercompressibility Factor Fpv Gases actually behave in a manner slightly different from what the ideal gas laws indicate. This deviation depends on the molecular composition of the gas and the specific gravity as well as the pressure and temperature. Natural gas, for instance, compresses by a greater amount than that computed by Boyle s Law and hence the term supercompressibility is used for this deviation. It is small at very low pressure, but becomes substantial as the pressure increases. The Mercor Mini automatically applies the supercompressibility factor and therefore the equation for total volume correction which the Mercor Mini applies to metered volume, is expressed as: Vb = Vm x Fp x Ft x (Fpv) 2 Where: Vb = volume corrected to base conditions Vm= metered volume read from the meter index Fp = pressure factor Ft = temperature factor Fpv= supercompressibility factor determined from AGA 3 and NX 19, the AGA Manual for Determination of Supercompressibility Factors for Natural Gas. The values of Fpv are derived in the tables for use with orifice meters, which are square root function measurements. So the flow equation for linear volume meters must square the value of Fpv. The Mercor Mini automatically squares the supercompressibility factor displayed, which is based on the pressure and temperature sensed at the meter. The resulting volume readout is corrected for pressure, temperature, and supercompressibility. Page 9

10 MERCOR MINI SIMPLIFIED BLOCK DIAGRAM LCD DISPLAY DISPLAY DRIVER DISPLAY INTERFACE DISPLAY BOARD MAG READ SWITCH FIRMWARE EPROM BATTERY J3 MAIN BOARD J7 J8 VOLTAGE REGULATORS CASE DOOR J6 SERIAL INTERFACE CPU FIELD CALIBRATOR INTERFACE J2 MERCOR MINI FIELD CALIBRATOR A/D CONVERTER J4 CORVOL PULSES & ALARM TB1 SWITCH INTERFACE J9 CASE TEMP ANALOG MULTIPLEXER J10 J5 AUX CORVOL PULSE BOARD METER PULSE BOARD TB1 PRESSURE TRANSDUCER TEMPERATURE PROBE MERCOR MINI CASE MECHANICAL UNCORRECTED INDEX (UMB) RS-232 SERIAL DATA AUX CORVOL PULSES CORVOL PULSES UNCVOL PULSES Page 10

11 5.0 HOW THE MERCOR MINI WORKS Refer to the simplified block diagram on page 4. The Mercor Mini is a dedicated microcomputer that uses precision sensors to measure gas pressure and temperature and corrects metered volume. The electronic circuits are powered by the battery pack located in the case door. The battery voltage is regulated to the various voltages required by the remaining circuits. While in the Corrector Mode, most of the electronic circuitry is in an unpowered (asleep) state. When the magnet disc rotates and actuates the input switches, the electronics are energized and begins its correction cycle. The input switches not only 'wakes-up' the electronics, but are also the input for uncorrected volume. The volume that each input closure represents is defined by item code 098. Once the instrument 'wakes-up', the operating code in the firmware chip instructs the CPU (microprocessor) to obtain analog measurements. The four analog signals, gas pressure, gas temperature, battery voltage and case temperature, are multiplexed through the A/D converter and sent to the microprocessor. The microprocessor converts the digitized analog signals to an equivalent numeric value and stores this information in memory. Gas Pressure is stored at item code 008, Gas Temperature is stored at item code 026, Battery Voltage is stored at item code 048 and Case Temperature is stored at item code 031. After all of the measurements are obtained, the microprocessor compares the measured values to the parameter limits already in memory, i.e., pressure low limit, temperature high limit, battery low limit, etc. If any of the measured parameters are out of range, the microprocessor will jump to an alarm subroutine as described by the instrument's operating code. Except for battery Shutdown Voltage limit exceeded, the alarm subroutine activates the appropriate alarm item code, turns on the alarm indicator and transmits an alarm pulse out the alarm channel. After the alarm sequence is complete, the microprocessor resumes its normal process. At the time of a full 'wake-up', if the battery Shutdown Voltage low-limit (item code 50) is exceeded, the microprocessor activates the alarm indicator (all seven LCD decimal points are turned-on), transmits an alarm pulse on the alarm channel, spells out the word "HELP" on the LCD and removes power from all electronic circuits, except for the LCD. Under these conditions, the "HELP" message is displayed for as long as there is enough battery voltage to maintain the display. The Mercor Mini is no longer correcting the gas volume, however, the mechanical index is still functional. The only way to restore normal instrument operation is to remove the dead battery and replace it with a fresh one. After the alarm subroutine is complete, or if no alarm conditions are present, the microprocessor computes new correction factors based on the new measurements and parameters already in memory. Parameters in memory are items such as; Base Pressure, Base Temperature, Specific Gravity, etc. The new correction factors are then applied to the uncorrected volume input to obtain the corrected volume. The amount of corrected volume just calculated is added to the corrected volume stored at item code 000. The uncorrected volume just received is also added to the previous uncorrected volume stored at item code 002. Page 11

12 When the microprocessor has completed the updating of its memory registers and item codes, it will update the LCD with the new corrected volume information. The microprocessor will then power down most of the main board circuits and transmits corrected volume pulses, if item code 093 was configured for "CORVOL OUT". Otherwise, the main board will go back into the 'asleep' mode waiting for the next uncorrected volume input pulse. Two other conditions can cause the Mercor Mini to 'wake-up' while in the Corrector Mode. They are; a Mag Wand Input and a Serial Communication Link. A Mag Wand Input is caused by passing a magnetic wand across the Mag Read Switch located on the LCD Display Board. A Mag Wand Input will cause the microprocessor to initiate the Meter Reader Mode as described in section 8. A 'wake-up' caused by a Serial Communication Link will allow the instrument to 'talk' to serial devices connected to the RS-232 port. In both cases, the microprocessor will initiate a full correction cycle as described above. After the completion of the correction cycle, most main board circuits will remain energized while the instrument is performing the user requested tasks. 5.1 Drive Input A universal mounting bracket, containing a standard digital index for indicating uncorrected volume of gas, is used to adapt the Mercor Mini to the meter. A reversing gear mechanism permits changing the index rotation to match meter wriggler rotation (see figures 7 and 8). Input of uncorrected volume to the processor board is made by magnetically operated reed switches. The magnet is located on a disc/shaft directly driven from the index (see figure 1). There is very little torque loading on the meter. The dual input switches allow continued operation if one switch fails. Input switch #1 is located along the right edge of the Input Switch Board (S1) and switch #2 is located just to its left (S2). If a switch failure is detected, an alarm is displayed. 5.2 Pressure System The pressure sensing system incorporates a precision strain gage pressure transducer, located inside the Mercor Mini housing with a 1/4" NPT female case connection. A valve kit with shut-off valve, tubing and fittings is optionally available to make the pressure connection to the meter. A plug-in cable is used to make the connection from the pressure transducer to the main circuit board. 5.3 Temperature System The temperature system consists of a highly stable, solid state transducer, connected to the Mercor Mini through a 6 foot length of armored conductor. The probe is 1/4" diameter by 9 inches long and is provided with a slip-along fitting for the matching thermowell in the meter piping. 5.4 Supercompressibility Correction Supercompressibility correction is included in the basic calculations which the Mercor Mini makes on metered volume. The unit is configured with the values for specific gravity, mol percent of N2 and CO2, and makes continuous correction for the specified gas composition based on actual sensed pressure and temperature. It displays the Fpv value but in making the supercompressibility correction it uses (Fpv) See section 4.3. Page 12

13 TEMPERATURE CIRCUIT BD. CONNECTOR PRESSURE CIRCUIT BD. CONNECTOR PRESSURE TRANSDUCER TEMPERATURE ARMOR INDEX SWITCH BD. MERCOR MINI INPUT SYSTEMS Fig.1 MAGNET DISC 5.5 Information Display A single 8 digit, 1/2" high numeric display is used in the Mercor Mini. The LCD (Liquid Crystal Display) normally displays the corrected volume with 4, 5, 6, 7, or 8 digits displayed. The LCD is also used to display an alarm condition and to display the items configured into the Meter Reader List. 5.6 Computation Intervals The Mercor Mini's computation interval is referred to as a 'Full Wake-up'. During a full wake-up, power is applied to the electronic circuits that were 'Asleep' so that pressure, temperature and voltage measurements may be obtained. A new Total Correction Factor is calculated so that the LCD and volume registers can be updated. The measured parameters are compared to the alarm limits and an alarm is triggered if limits are exceeded. After completion of these tasks, the circuitry will return to the 'Asleep' mode and begin transmitting corrected volume pulses, if item code 093 is set for "CorVol" out. The full wake-up interval can be selected by changing the value of the Revs Per Wake-up parameter (N), item code 124. Values for N can be from 1 to 255, the default selection is once every ten (N=10) meter revolutions. Instrument wake-up due to meter rotation other than the Nth revolution are referred to as 'Intermediate Wake-ups'. During an intermediate wake-up, gas pressure and gas temperature are not measured and the LCD is not updated. However, the last calculated correction factors are used to update the volume registers. If the Mini has been configured to output corrected volume pulses, the output pulses will be generated at the end of each intermediate wake-up. Since the analog circuits and the LCD display circuits are not active during an intermediate wake-up, much less battery power is used, compared to an instrument with Revs Per Wake-up equal to one (N=1). Page 13

14 5.7 Access Levels for Operating Personnel There are five levels of instrument access available on the Mercor Mini for operating personnel. The first level, referred to as the Corrector Mode, displays the corrected volume on the LCD and the uncorrected volume on the digital mechanical index. The Corrector Mode also provides a visual indication for instruments in an alarm condition. The second level available is referred to as the Meter Reader Mode. Meter readers can use a magnetic wand to scroll the values of specific items on the LCD. Uncorrected and corrected volumes, a limited number of pre-specified values such as gas pressure and temperature, battery voltage, and any alarms that may be activated, can be part of the meter reader list. The meter reader cannot make any changes that will effect the configuration of the Mercor Mini. The third level of access available is called: Level 1 Access Mode. This level of access requires an IBM compatible computer, Mini-Link software, an interface cable and the Level 1 Access Code. Once Level 1 Access has been gained, the operator can perform field calibration checks and make adjustments if necessary. Additionally, clearing alarms, performing certain diagnostic functions and changing the configuration of authorized items are possible. Access at the fourth level is reserved for the instrument technician and is referred to as Level 2 Access Mode. Access to this level requires an IBM compatible computer, Mini-Link software, an interface cable and the Level 2 Access Code. Once Level 2 Access is gained, the instrument technician can reconfigure the Mercor Mini instrument. Any and all items code values may be changed, including Level 1, Level 2 and the Instrument Access Codes. The Authorization Table may also be modified, which will control what item values may be changed during Level 1 Access. Serial Communication Mode is the last type of access to the Mercor Mini. In this mode, RS-232 devices connected to the serial port can transfer data to or from the instrument. To insure data integrity, the serial communications protocol incorporates data error checking. Note: Level 1 and Level 2 Access are computer software functions only. Even after gaining Level 1 or Level 2 Access, changes to the instrument's configuration are not possible until an Instrument Access Code is entered, when requested. Refer to section 7.3 and 7.4 for more information. The Mercor Mini continues to recognize meter pulses while in the Meter Read, Level-1, Level-2 and Serial Communication Modes. Upon exiting any serial link access, the Mini will perform a Full Wake-up just before returning to the Corrector Mode. Following a meter reader access, the instrument will return to the Corrector Mode; a) without a wake-up, if there were no meter rotations during the meter reader access. b) after an intermediate wake-up with any number of meter rotations and N greater than one. c) after a full wake-up with any number of meter rotations and N equal to one. 5.8 Power Supply The standard power for the Mercor Mini is supplied by a disposable alkaline battery pack ( ), located inside the instrument door. Dual power cable connectors are provided on the main circuit board so that battery packs can be changed without removing power from the unit. The Mercor Mini can also operate from several optional power supplies, which include: Lithium Power Pack ( ), D-cell Alkaline Receptacle Power Pack ( ) and a line operated DC Power Supply ( ). Page 14

15 6.0 HOW TO INSTALL AND OPERATE THE MERCOR MINI 6.1 Receiving When the instrument is delivered, be sure that all parts are received in good condition. Check the packing list to make certain the shipment is complete. Report any shortage or shipping damages to your Mercury Representative. Immediately file any damage claims with the carrier who delivered the shipment. 6.2 Function Check Open the case door and check for any loose parts and verify that all connectors are properly seated. The battery pack is packaged separately and must be installed on the inside of the case door. Mount the battery pack and plug in the battery connector at either J7 or J8 (see figure 2 below). Install the metal cover provided over the battery pack. If the Mercor Mini is displaying digits on the LCD (probably all zeros) then the unit is now ready for functional checks. Note: All of the function checks in Section 6 assumes that the instrument is configured with default parameters, as indicated in Section 10. The default configuration has assigned a commonly used Meter Reader List, Pressure, Temperature and Volume Units, Alarm Limits, etc. If the Meter Reader List is something other than the default, most checks can still be performed, but the results may vary slightly. BATTERY CABLE CONNECTOR J7 CONNECTOR J8 POWER CONNECTION TO THE MAIN CIRCUIT BOARD Fig. 2 Page 15

16 6.3 Pressure Function Check - Gauge Pressure Transducer Use a mag wand to scroll through the Meter Reader List and stop at the live pressure display. Refer to section 8 if additional information is required in using the Meter Reader List. With no pressure connected, the LCD will display a value very close to zero - typically within plus or minus 0.5% of full scale. To check the pressure measuring system, apply some amount of pressure (but less than the full range of the transducer) and observe the LCD value increases. There is a 30 minute time-out before the instrument automatically reverts back to the Corrector Mode. Use the mag wand and scroll through the remaining items until the instrument is back to the Corrector Mode. 6.4 Pressure Function Check - Absolute Pressure Transducer Use a mag wand to scroll through the Meter Reader List and stop at the live pressure display. Refer to section 7 if additional information is required in using the Meter Reader List. With no pressure connected, the LCD will display a value very close to local atmospheric pressure - typically within plus or minus 0.5% of full scale. To check the pressure measuring system, apply some amount of pressure (but less than the full range of the transducer) and observe the LCD value increases. There is a 30 minute time-out before the instrument automatically reverts back to the Corrector Mode. Use the mag wand and scroll through the remaining items until the instrument is back to the Corrector Mode. 6.5 Temperature Function Use a mag wand to scroll through the Meter Reader List and stop at the live temperature display. Refer to section 7 if additional information is required in using the Meter Reader List. The LCD will display a value very close to ambient temperature - typically within plus or minus 0.5 degrees F. To check the temperature measuring system, grab the temperature probe near the tip and observe the LCD value increase. There is a 30 minute time-out before the instrument automatically reverts back to the Corrector Mode. Use the mag wand and scroll through the remaining items until the instrument is back at the Corrector Mode. 6.6 Volume Function Check While in the Corrector Mode, note the corrected volume reading. Rotate the index input wriggler in one direction for ten (10) revolutions. Verify that the volume has increased by the expected amount. With zero applied pressure and at room temperature, the additional corrected volume should be essentially equal to the index rate times the number of turns (10) of the wriggler. Page 16

17 6.7 Battery Pack Check Use a mag wand to scroll through the Meter Reader List and stop at Item# 48, Battery Voltage display. Refer to section 8 if additional information is required in using the Meter Reader List. For a fresh, standard alkaline battery pack, the LCD will display a value very close to 8.60 volts DC. If a fresh lithium battery pack is installed, the LCD will display a value between 6.60 and 6.90 volts DC. There is a 1 minute timeout before the instrument automatically reverts back to the Corrector Mode. Use the mag wand and scroll through the remaining items until the instrument is back to the Corrector Mode. 6.8 Changing Batteries The power supply for the Mercor Mini is a replaceable battery pack, located inside the instrument case door. The service life of the battery pack is nominally one (1) year under normal use, with considerable reserve to allow for battery replacement after the low battery alarm occurs. If the battery voltage drops below the preset value, a BATTERY LOW alarm occurs (see the section 8.2 to clear alarms). When this alarm occurs, the battery pack should be replaced. A dual cabling system allows batteries to be changed without removing power from the unit. As with any computer, IT IS IMPORTANT NOT TO DISCONNECT POWER WHILE THE UNIT IS OPERAT- ING. To replace a battery pack, refer to figures 2 through 4 while following the procedure below. 1) Loosen the three (3) slotted screws (item A) and remove the aluminum battery cover (item B), see figure 3. 2) Plug in the new battery's cable at the main board connector J7 or J8 (see figure 2). 3) Unplug and remove the old battery pack (item C). 4) Install the new battery pack by hanging its aluminum plate on the two (2) hanger screws (item A). Replace the aluminum cover and tighten all three (3) slotted screws (item A). 5) Position the battery cable in the white spring clip (D). Page 17

18 BATTERY COVER (B) SLOTTED SCREW (A) NUMERIC DISPLAY RIBBON CABLE SPRING CLIP (D) INSIDE CASE DOOR Fig. 3 CASE DOOR BATTERY HANGER PLATE BATTERY PACK (C) BACK PLATE INSIDE CASE DOOR Fig. 4 BATTERY CABLE Page 18

19 6.9 Battery Shutdown - HELP Display Should the BATTERY LOW alarm be ignored and the battery pack not be replaced, the voltage will eventually decrease to the shutdown level. The battery SHUTDOWN VOLTAGE is displayed at Item 50. When the battery shutdown level is reached, the Mercor Mini automatically shuts down and will no longer operate as a corrector. The "..H.E.L.P.." message will appear in the numeric display to indicate the instrument has a dead battery. All of the configured parameters and accumulated volumes will be retained in memory. To resume operation, disconnect and remove the old battery pack. Mount the new battery pack as outlined in section 6.8. Note: Wait for the rotating index magnet to be away from the switch board and toward the front of the case. When it is, plug in the battery cable and the last corrected volume will appear in the numeric display. The volume values (Items 0 and 2) should be checked and updated to the current adjusted or estimated values (if this is your company s policy) based on the current reading of the mechanical uncorrected index. Also verify the configured values (Base Pressure, Atmospheric Pressure, Base Temperature, Specific Gravity, etc.) to assure yourself that all parameters are correct Pulse Output Terminal Connections The corrected and uncorrected output pulse terminal strip locations are shown in figure 5. The corrected volume pulse output terminal strip is located in the lower left portion of the Mercor Mini's main circuit board. It contains five (5) screw terminals to accommodate output connections for PULSER A and the alarms channel. The pulser switches are solid state opto-isolators that are compatible with most data collection and communication systems. The standard corrected volume output pulse is a Form-C type (labeled KYZ), requiring three (3) pulser wires. The standard alarm output pulse is a Form-A type requiring two (2) wires. The uncorrected volume pulse output terminal strip is located on the small circuit board just behind the rotating magnet disc. These three (3) screw terminals (labeled COM, NO & NC) accommodate output connections for the uncorrected volume pulses. Since the uncorrected volume pulse circuit uses a three terminal reed switch, this output may be wired as a Form-A (2-wires) or Form-C (3-wires) type output. CORRECTED VOLUME TERMINAL STRIP INDEX SWITCH BD UNCORRECTED VOLUME OUTPUT TERMINAL STRIP Fig. 5 Page 19

20 6.11 Instrument Mounting The Universal Mounting Bracket (UMB) permits installation of the Mercor Mini on American, Rockwell, Romet, or Roots meters. The UMB housing may be rotated about the base plate so that the instrument and index will face in any of four (4) directions, by removing all four (4) screws which attach the base plate to the bracket housing. Replace them after you have repositioned the UMB housing. Refer to figure 6 and the following procedure when installing the Mercor Mini on a meter. 1) Position the universal mounting bracket (UMB) and gasket on the meter mounting plate. Install the four (4) mounting bolts and tighten. 2) Connect the pressure tubing to 1/4" NPT case pressure connector on rear of instrument case. 3) Install the temperature probe slip-along fitting into the thermowell. 4) Insert the temperature probe into the slip-along fitting and tighten. CASE BACK 1/4" NPT CASE PRESSURE CONNECTOR RS-232 SERIAL PORT PULSE OUTPUT HUBBELL FITTING UMB (BACK) TEMPERATURE PROBE ARMOR MOUNTING BOLTS (4) MERCOR MINI (BACK) Fig. 6 Page 20

21 6.12 Check Rotation A reversing gear in the Universal Mounting Bracket (UMB) permits either clockwise or counterclockwise meter rotation to drive the Mercor Mini. Before installing the instrument, make the following checks: 1) Determine meter drive rotation by looking down on meter driving dog. Note whether it rotates clockwise (CW) or counterclockwise (CCW). 2) Inspect mounting bracket internal gearing by looking through opening in baseplate. - If meter driving dog rotates CW, the lower bevel gear should be DOWN, against bar (see figure 7). - If meter driving dog rotates CCW, the lower bevel gear should be UP, against hub of upper bevel gear (see figure 8). 3) To change rotation, if necessary: - Remove transparent index cover. - Remove two (2) thumbscrews and lift out index. - Use the supplied spline wrench to loosen set screw in the lower bevel gear. - Shift gear down against cross bar or up against upper gear, depending on rotation you are setting. When shifting up, driving pin in lower gear should engage mating hole in hub of upper gear. - Tighten set screw in lower gear against flat surface of shaft. - Replace index... use caution... be sure bevel gears mesh properly with face gear in both directions. - Replace transparent index cover. NOTE: When installing instruments on American Meter Heads, request American Meter Mounting Kit part number This kit consists of special mounting bolts and a round cover plate that is required on some meters to cover the exposed area. BEVEL GEAR DOWN FOR CW Fig.7 BEVEL GEAR UP FOR CCW Fig.8 Page 21

22 7.0 MERCOR MINI OPERATING MODES While in service, the Mercor Mini is always in one of five operating states. Its operation in each state is well defined and suited to a particular purpose. The five states are referred to as Operating Modes and are: Corrector Mode Meter Reader Mode Level 1 Access Mode Level 2 Access Mode Serial Mode In the first three Modes above, the Mercor Mini receives inputs from the meter on which it is mounted (uncorrected volume); the pressure transducer (metering pressure); and the temperature probe (metering temperature). In the Level 2 Access Mode, The Mercor Mini would normally be on the bench in the meter shop or instrument shop. 7.1 Corrector Mode The Mercor Mini normally operates in the Corrector Mode. The other four Modes: Meter Reader, Level 1 Access Mode, Level 2 Access Mode and Serial Mode always return to the Corrector Mode when completed. The corrected volume continuously appears on the LCD display. The uncorrected volume is displayed on the mechanical index in the mounting bracket. Uncorrected volume pulses are detected by magnetically actuated reed switches at each meter revolution. The instrument electronics are normally in a stand-by (asleep) mode, but are activated (wake-up) by an input pulse generated from the reed switches. During a wake-up, the instrument measures the gas pressure and temperature, then calculates the correction factors and updates the corrected volume on the LCD display. The electronic circuitry returns to the asleep mode to conserve battery power until the next full rotation of the meter output shaft. 7.2 Meter Reader Mode This mode provides the meter reader with access to a number of displays in addition to the corrected volume, without opening the door of the Mercor Mini. By running a magnet activator along the right edge of the display window on the door, the meter reader can step through a sequence of readings. These readings include up to 15 parameter values, alarms, live gas pressure and live gas temperature, if desired. At the time the meter reader activates the unit by means of the first mag wand input, the unit updates all measurements and displays the LCD Display Test. This is to verify that all seven segments and decimal points of the eight digit LCD are functional. The uncorrected volume continues to totalize on the mechanical index. When the instrument receives a mag wand input while the last Meter Reader List item is displayed, the unit will return to the Corrector Mode. If the Meter Reader List sequence has not been completed, the unit returns to the Corrector Mode automatically after a one minute timeout period (unless the instrument is displaying live pressure or live temperature, in which case, the time-out period is 30 minutes). Input pulses which occurred while the unit was in Meter Reader Mode have been stored and will be processed the next time volume is totalized. Page 22

23 7.3 Level 1 Access Mode Level 1 Access is considered a lower level access to instrument functions and is gained through the use of a laptop computer. Level 1 Access is a software function using the instrument's companion software Mini-Link, but requires the instrument to be connected to the computers RS-232 serial port. The user must enter a five digit access code (default: 11111) at the computer's keyboard. (See Mini-Link SOFTWARE USER'S Guide for additional information on using Mini-Link functions.) Level 1 Access permits instrument calibration for pressure and temperature. A limited number of parameters may be displayed and changed if authorized. Alarms may also be viewed and cleared. When attempting to establish a serial link to the instrument, the software will request the user to input a five digit Instrument Access Code. This access code is necessary to maintain instrument security. The default Instrument Access Code is: This access code may be changed if desired, but requires Level 2 Access. While the instrument is in Level 1 Access, the unit keeps track of incoming uncorrected pulses. Corrected and uncorrected totals are updated when leaving Level 1 Access, using values of pressure and temperature measured just before exiting. The pressures and temperatures applied during any calibration process are not used for any of the correction calculations. Note: Be sure the line pressure and temperature are restored before exiting Level 1 Access, otherwise improper correction factors will be applied to any stored input pulses Level 2 Access Mode The Level 2 Access Mode allows the factory or the user to configure the Mercor Mini instrument. Level 2 Access is considered a higher level access to all instrument functions and is gained through the use of a laptop computer. Level 2 Access is also a software function using the instrument's companion software Mini-Link. The user must enter a five digit access code (default: 22222) at the computer's keyboard. (See Mini-Link SOFTWARE USER'S Guide for additional information on using Mini-Link functions.) Level 2 Access permits instrument calibration and configuration. Any instrument parameter may be displayed and changed. When attempting to establish a serial link to the instrument, the software will request the user to input a five digit Instrument Access Code. This access code is necessary to maintain instrument security. The default Instrument Access Code is: This access code may be changed, if desired, when the user is at Level 2 Access. While the instrument is in Level 2 Access, the unit keeps track of incoming uncorrected pulses. Corrected and uncorrected totals are updated when leaving Level 2 Access, using values of pressure and temperature measured when Level 2 Access is left. The pressures and temperatures applied during any calibration process are not used for any of the correction calculations. Note: Be sure the line pressure and temperature are restored before exiting Level 2 Access, otherwise improper correction factors will be applied to any stored input pulses. Page 23

24 7.5 Serial Mode The Mercor Mini's Serial Mode permits data transfer to or from the instrument's on-board memory. Any RS-232 serial device can be connected to the instrument's serial port, but the serial device must be able to communicate using Mercury's serial data protocol. Modem operation is supported by Mini-Link software (incorporating Mercury Protocol) and may be used to transfer data from a remote location to a host computer. All other RS-232 devices (such as Automatic Meter Reader equipment) would require Mercury's Protocol in the software's communication driver. Refer to figure 9 below when making connections to the RS-232 serial port. The I/O cable (p/n ) incorporates alignment tabs and a locking ring. Align the widest tab to the top and push connector into the port as far as it will go. Turn the outer locking ring clockwise to lock the cable in place. Locate the serial port on the laptop computer, it may be labeled COM1, COM2, RS-232 or just Serial. Connect the I/O cable DB-9 connector to the laptop computer serial port. Refer the Mini-Link manual for further information. Serial Port (i.e.com1,com2,) Laptop Computer Back View Widest Notch Up Locking Ring DB-9 Connector RS-232 Port I/O Cable P/N Fig. 9 Page 24

25 8.0 METER READER MODE OPERATION During normal operation, the Mercor Mini is operating in the Corrector Mode. To obtain information in addition to corrected and uncorrected volume, any person with a magnetic wand may access the instrument's Meter Reader Mode. The Meter Reader Mode provides the ability to display a predetermined number of items on the LCD display without opening the instrument door. The number of selected items to be viewed can range from none to seventeen. The selected items may be any of the instrument's item codes. See section 10 for a complete list of item codes. Upon entering the Meter Reader Mode, any active alarm(s) is always displayed before the selected item codes are displayed. When enabled, the Mag Alarm Acknowledge (item # 128) will permit all alarms to be cleared using the mag wand. If desired, live gas pressure and live gas temperature may be included as part of the meter reader list. While displaying live pressure or live temperature, a single point calibration may be performed if a Mercor Mini Field Calibrator is connected to connector J2 on the main circuit board. The live parameters have a 30 minute time-out to provide enough time to complete the calibration process. 8.1 Gaining Access To Meter Reader Mode When the Mercor Mini is in the Corrector Mode, run the red tip of the magnet activator (mag wand) along the right side of the Corrected Volume LCD window, see figure 10. Upon entering the Meter Reader Mode, the LCD will go blank and the transmission of corrected volume pulses is suspended. The instrument takes a pressure and temperature measurement and recalculates all correction factors before the item codes are updated. NUMERIC DISPLAY MAGNETIC ACTUATOR (Start at top of label and stroke downward to bottom right corner) MAG WAND POSITION TO ACTIVATE METER READ MODE Fig. 10 Page 25

26 8.2 Default Meter Reader Display While in the Meter Reader Mode, the Mercor Mini continues to recognize and accumulate meter input pulses. Also, 1-minute and 30-minute Time-outs are used to automatically return the instrument to the Corrector Mode. By design, the Corrector Mode requires much less electrical energy than all other operating modes. The time-out periods are safeguards to insure that the batteries are not needlessly wasted. Refer to figure 12 which is a flowchart of the default meter reader list. After the initial mag wand input, the Mini's operating program determines if there are any active alarms. The presence of active alarms, while in the Corrector Mode, is indicated by displaying all decimal points in the corrected volume display, similar to the Display Test as indicated in figure 11. If there are active alarms, all active alarm codes are displayed before the normal meter reader list items are displayed. Note; While in the alarm display routine, all alarms may be cleared, if the instrument is allowed to timeout during the display of the "E.E.E.E.E.E.E.E" and Item Code 128 is set to "Enable". If the instrument receives a mag wand input during the "E.E.E.E.E.E.E.E" display, the alarms are not cleared and the sequence moves to the "Display Test" function. The "Display Test" is always the first meter reader list item, it cannot be de-selected. It is used to provide a visual means of verifying that all LCD segments and decimal points are fully functional. If the "Display Test" does not appear as in figure 11, the remaining item code values may not be fully correct. When the mini receives a mag wand input during the "Display Test", the current value for Uncorrected Volume is displayed. Each additional mag wand input will cause the next item code value to scroll onto the LCD. The items assigned to the default meter reader list are comprised of Item Codes , 129 and Listed below is the default meter reader list in the proper sequence: ITEM# ITEM DESCRIPTION --- DISPLAY TEST 002 UNCORRECTED VOLUME 000 CORRECTED VOLUME --- GAS PRESSURE (LIVE) --- GAS TEMPERATURE (LIVE) 200 SITE ID 113 HIGH RESOLUTION CORVOL 013 BASE PRESSURE 014 ATMOSPHERIC PRESSURE 025 TRANSDUCER RANGE 044 PRESSURE CORRECTION FACTOR 043 TOTAL CORRECTION FACTOR 048 BATTERY VOLTAGE 031 CASE TEMPERATURE Page 26

27 When the last meter reader item is displayed, the next mag wand input will cause the instrument to return to the Corrector Mode. Upon entering the Corrector Mode, any stored input pulses are used to update the LCD and volume registers. Listed below are necessary item codes required to create the default Meter Reader List. Item Code # Item Legend Selected Item Description 075 Mag List 2 Item #1 200 Site ID 076 Mag List 2 Item #2 113 High Resolution CorVol 077 Mag List 2 Item #3 013 Base Pressure 078 Mag List 2 Item #4 014 Atmospheric Pressure 079 Mag List 2 Item #5 025 Transducer Range 080 Mag List 2 Item #6 044 Pressure Correction Factor 081 Mag List 2 Item #7 043 Total Corrector Factor 082 Mag List 2 Item #8 048 Battery Voltage 083 Mag List 2 Item #9 031 Case Temperature 129 Live Display Enable Live P&T Live Pressure & Temperature 130 Mag List 1 Item #1 002 Uncorrected Volume 131 Mag List 1 Item #2 000 Corrected Volume 132 Mag List 1 Item #3 255 End-of-List 133 Mag List 1 Item #4 255 End-of-List 134 Mag List 1 Item #5 255 End-of-List 135 Mag List 1 Item #6 255 End-of-List CORRECTED VOLUME MCF METER READER LIST: UNCORRECTED VOLUME CORRECTED VOLUME GAS PRESSURE GAS TEMPERATURE SELECTED ITEMS 1-9 CCF MCF Display Test Fig. 11 Page 27

28 CORRECTOR MODE no MAG WAND INPUT yes ALARMS PRESENT? no yes no yes 1 MINUTE TIME-OUT no 1 MINUTE yes TIME-OUT no yes 1 MINUTE TIME-OUT DISPLAY TEST no MAG WAND INPUT yes UNCORRECTED VOLUME no MAG WAND INPUT yes CORRECTED VOLUME no MAG WAND INPUT yes CHANGE TO NEXT ALARM ALARMS CODE DISPLAY MAG WAND no INPUT yes yesadditional ALARMS? no E.E.E.E.E.E.E.E DISPLAY ITEM # 128 no ENABLED yes no 1 MINUTE TIME-OUT no yes no 1 MINUTE TIME-OUT yes MAG WAND INPUT yes LIVE PRESSURE yesmag WAND INPUT no no yes 30 MINUTE TIME-OUT no MAG WAND INPUT yes no 1 MINUTE TIME-OUT yes LIVE TEMPERATURE ALARMS CLEARED no yes 30 MINUTE TIME-OUT no yes 1 MINUTE TIME-OUT no MAG WAND INPUT yes SELECTED ITEM # 1-9 no MAG WAND INPUT yes ALARM CODES E-069 PULSER "A" LIMIT ALARM E-099 BATTERY LOW VOLT LARM E-102 INDEX SW#1 FAULT ALARM E-103 INDEX SW#2 FAULT ALARM E-104 A/D FAULT ALARM E-105 PRESS OUT OF RANGE ALARM E-106 TEMP OUT OF RANGE ALARM LAST ITEM? yes no CHANGE TO NEXT ITEM Default Meter Reader List Fig. 12 Page 28

29 8.3 Enhanced Meter Reader Display The default meter reader list was provided to allow a basic instrument to 'look' and 'act' like earlier units with firmware version less than Starting with firmware version 1.30, additional features are included to allow the user more flexibility in configuring the meter reader list. Upon entering the Meter Reader Mode, all active alarms are displayed prior to the display of the configured meter reader list, as described in section 8.2. Also, the "Display Test" remains the first meter reader list item and cannot be de-selected. The Display Test provides a visual means of verifying that all LCD segments and decimal points are fully functional. If the "Display Test" does not appear as in figure 11, the remaining item code values may not be fully correct. The meter reader list is now divided into five parts and can only be displayed in the following order: MAG LIST SECTION DESCRIPTION 1 ALARM CODES (Displayed only if any alarms are active) 2 DISPLAY TEST 3 MAG LIST 1 4 LIVE PARAMETER DISPLAY 5 MAG LIST 2 Except for the Alarm Codes and Display Test, each sub-section listed above is configurable. Refer to the descriptions below and the flowchart in figure 12 for configuration details and the sequence of events that occur during a non-default meter reader list. 8.4 Mag List 1 Mag List 1 consists of six item codes ( ) which define what items will appear in section 3 of the meter reader list. Normally, corrected and uncorrected volumes are part of Mag List 1. However, any item code can be placed into Mag List 1. If less than six items are required, place the value 255 into the item code location after the last desired Mag List 1 item. When the Mag List 1 item values are displayed, all eight digits on the LCD are used, unless the volume items are configured for fewer digits. It is possible to blank up to four digits on the left side of the LCD using Item Codes 096 and 097. Example #1: Suppose Site ID, Corrected Volume, Uncorrected Volume, Gas Pressure and Gas Temperature are the only items desired for Mag List 1. Since only five items are listed, the Mag List 1 configuration would appear as follows: Item Code # Item Legend Selected Item Description 130 Mag List 1 Item 1 # 200 Site ID 131 Mag List 1 Item 2 # 000 Corrected Volume 132 Mag List 1 Item 3 # 002 Uncorrected Volume 133 Mag List 1 Item 4 # 008 Gas Pressure 134 Mag List 1 Item 5 # 026 Gas Temperature 135 Mag List 1 Item 6 # 255 (End-Of-List) Page 29

30 8.5 Live Parameters Display The Live Parameter Display will allow up to two parameters to appear in section 4 of the meter reader list as live measurements. The only two parameters that may be a live display are: Live Gas Pressure and Live Gas Temperature. These should not be confused with item codes 008 (Gas Pressure) and 026 (Gas Temperature). If item codes 008 and 026 are part of the meter reader list, the values for gas pressure and gas temperature are placed into memory at the time of the initial mag wand input. If item codes 008 or 026 are encountered during a Meter Reader Mode, the values previously placed in memory are recalled and displayed. The purpose of providing a Live Gas Pressure and Live Gas Temperature is two-fold. First, it will allow the meter technician to monitor the gas pressure without attaching a portable pressure gauge. Second, the meter technician can attach a Mercor Mini Field Calibrator to J2 on the main circuit board and perform a single point pressure or temperature calibration. Hence, the instrument can be calibrated without the need of a laptop computer. See section 9 for more information on instrument calibration. The option selected at Item Code 129 (Live Display Enable) determines which live parameter, if any, will be displayed after the display of the last Mag List 1 item. The available selections using Mini-Link are: None Live P Live T Live P&T Example #2: Suppose Site ID, Corrected Volume, Uncorrected Volume, Live Gas Pressure and Live Gas Temperature are the only items desired for the meter reader list. Since items 008 and 026 will not provide a live reading, it will be necessary to configure item 129 as shown below: Item Code # Item Legend Selected Item Description 075 Mag List 2 Item 1 # 255 (End-Of-List) 129 Live Display Enable Live P&T Live Pressure & Temperature 130 Mag List 1 Item 1 # 200 Site ID 131 Mag List 1 Item 2 # 000 Corrected Volume 132 Mag List 1 Item 3 # 002 Uncorrected Volume 133 Mag List 1 Item 4 # 255 (End-Of-List) 134 Mag List 1 Item 5 # 255 (End-Of-List) 135 Mag List 1 Item 6 # 255 (End-Of-List) Note: Remember that all Mag List 1 items have a 1-minute time-out and both live parameters have a 30- minute time-out. Page 30