Operating manual ba55321de LRD 325-... Conductivity measuring cell to be installed in pipelines ba55321de01 12/00 27
Accuracy when going to press The use of advanced technology and the high quality standard of our instruments are the result of a continuous development. This may result in differences between this operating manual and your instrument. Also, we cannot guarantee that there are absolutely no errors in this manual. Therefore, we are sure you will understand that we cannot accept any legal claims resulting from the data, figures or descriptions. Warranty The designated instrument is covered by a warranty of 12 months from the date of purchase. The instrument warranty covers manufacturing faults that are discovered within the warranty period. The warranty excludes components that are replaced as part of maintenance, e.g. batteries. The warranty claim extends to restoring the instrument to readiness for use but not, however, to any further claim for damages. Improper handling or unauthorized opening of the instrument invalidates any warranty claim. To ascertain the warranty liability, return the instrument and proof of purchase together with the date of purchase freight paid or prepaid. Copyright Weilheim 2001, WTW GmbH& Co. KG Reprinting - even as excerpts - is only allowed with the explicit written authorization of WTW GmbH & Co. KG, Weilheim. Printed in Germany. 28
List of contents 1 General............................... 31 2 Safety................................ 33 2.1 Authorized use............................ 34 2.2 General safety instructions................... 34 3 Installation............................ 35 3.1 General.................................. 35 3.2 Installation in stainless steel adaptor............ 35 3.2.1 Installation in weld-in socket, EST-LRD... 35 3.2.2 Installation in adaptor socket, ADA-3/4 NPT 37 3.2.3 Installation in adaptor socket, ADA-G 1 Zoll 38 3.3 Installation in plastic adaptor.................. 39 3.3.1 Installation in glueing socket, ADA-LF-DN 20....................... 39 3.3.2 Installation in the ADA-LF-DN 20 glueing socket, using the ADA-DN 25... -DN 50 distance sleeves..................... 41 4 Maintenance, cleaning, disposal.......... 43 4.1 Aging of the measuring cell................... 43 4.2 Cleaning................................. 44 4.3 Disposal.................................. 44 5 Recommended accessories.............. 45 6 What to do if............................ 47 7 Technical data......................... 49 7.1 General features........................... 49 7.2 Electrical data............................. 51 29
List of contents 30
General 1 General Total view of the LRD 325-... Minimum immersion depth: 36 mm The technical measuring principle avoids interferences by primary or secondary polarization effects. This guarantees a high measuring accuracy. The modern epoxy casting technique reduces the danger of breaking the probe in rough industry use. 31
General Construction of the LRD 325-... 1 2 3 5 4 1 Cable with plug 2 Housing 3 Current electrode (ring) 4 Potential electrode 5 Temperature probe 32
Safety 2 Safety Target group Safety instructions This operating manual contains basic instructions that you must follow during the commissioning, operation and maintenance of the measuring cell. Consequently, all responsible personnel must read this operating manual before working. The operating manual must always be available within the vicinity of the measuring cell. The conductivity measuring cell was especially designed for the use in waste water treatment plants with heavily loaded waste water. Thus, we assume that, as a result of their professional training and experience, the operators will know the necessary safety precautions to take when handling chemicals. In the individual chapters of this operating manual, the following safety instructions indicate different danger levels: Warning indicates notes that have to be exactly observed to avoid possibly great danger for people. Caution indicates notes that have to be exactly observed to avoid possible slight injuries or damage to your instrument or the environment. Further notes Note indicates notes that draw your attention to special features. Note indicates cross references to other documents, e. g. operating manuals. 33
Safety 2.1 Authorized use The technical specifications as given in chapter 7 TECHNICAL DATA must be observed. Only the operation and running of the measuring cell according to the instructions given in this operating manual is authorized. Any other use is considered unauthorized. 2.2 General safety instructions Function and operating safety The conductivity measuring cell left the factory in a safe and secure technical condition. The smooth functioning and operational safety of the conductivity measuring cell can only be guaranteed if the generally applicable safety measures and the specific safety instructions in this operating manual are followed during operation. The smooth functioning and operational safety of the conductivity measuring cell can only be guaranteed under the environmental conditions that are specified in chapter 7 TECHNICAL DATA. The temperature range specified for using the conductivity measuring cell (chapter 7 TECHNICAL DATA) has to be observed. Protect your conductivity measuring cell especially against frost or overheating. Caution The conductivity measuring cell is only allowed to be opened by personnel authorized by WTW. 34
Installation 3 Installation 3.1 General Warning The installation may only be performed by specialists trained for this. Incorrect installation and its consequences are not covered by the manufacturer's warranty. Observe the local technical regulations for pressure vessels. 3.2 Installation in stainless steel adaptor 3.2.1 Installation in weld-in socket, EST-LRD Application Weld-in socket (1.4571 stainless steel) to weld into stainless steel pipes. EST-LRD Flow direction 35
Installation Welding the adaptor Observe the following points: Because of the tapered NPT screw thread, the thread opening of the adaptor has to point outwards. Install the adaptor in such a way that the medium flows through the slot of the LDR 325 in the flow direction. Warning Only authorized specialists are allowed to weld the adaptor and cut pipes! Screwing in the conductivity measuring cell 1 Wrap the thread of the LRD 325 with Teflon sealing tape. 2 Screw the measuring cell into the welded adaptor, EST-LRD. 36
Installation 3.2.2 Installation in adaptor socket, ADA-3/4 NPT Application NPT adaptor socket (1.4571 stainless steel) to increase the 1/2" NPT thread of the LRD 325 to 3/4". ADA-3/4 NPT Installation 1 Wrap the thread of the LRD 325 with Teflon sealing tape. 2 Screw the adaptor on the thread of the measuring cell; the thread opening of the adaptor points upwards. 3 Tighten the adaptor using a size 24 fork wrench. 4 Screw the measuring cell with the adaptor into the corresponding pipe cutout. 37
Installation 3.2.3 Installation in adaptor socket, ADA-G 1 Zoll Application Adaptor socket (1.4571 stainless steel) to install into a 1" pipe thread. ADA-G 1 Zoll Installation 1 Wrap the thread of the LRD 325 with Teflon sealing tape. 2 Install the adaptor in the pipe thread up to the stop; the thread opening of the adaptor points upwards. 3 Tighten the adaptor using a size 41 fork wrench. 4 Screw in the measuring cell with the ADA-G 1 Zoll adaptor. 38
Installation 3.3 Installation in plastic adaptor General The plastic adaptor is glued into a PVC pipe, preferably into a 90 T-piece or 90 crosspiece. Note Before applying the PVC glue (e. g. Tangit, Henkel company) to the adaptor, thoroughly clean and degrease the contact surfaces. Allow the glue to harden according to the manufacturer's instructions. 3.3.1 Installation in glueing socket, ADA-LF-DN 20 Application Socket (steel reinforced PVC) to glue into PVC pipe ends with a nominal diameter of DN 20. ADA-LF-DN 20 DN 20 Installation 1 Apply glue around the front outside part of the ADA-LF-DN 20 glueing socket. 39
Installation 2 Insert the glueing socket into the T-piece up to the stop while slightly rotating it, so that the glue is distributed evenly between the contact surfaces. 3 Allow the glue to harden. 4 Wrap the thread of the LRD 325 with Teflon sealing tape. 5 Tightly screw the measuring cell into the glueing socket. 40
Installation 3.3.2 Installation in the ADA-LF-DN 20 glueing socket, using the ADA-DN 25... -DN 50 distance sleeves Application Using the PVC distance sleeves, ADA-DN 25... ADA- DN 50, the ADA-LF-DN 20 glueing socket can be glued into pipe ends with a bigger nominal diameter. ADA-LF-DN 20 ADA-DN 32 (ADA-DN 25, ADA-DN 40, ADA-DN 50) Note All ADA-DN 25... ADA-DN 50 distance sleeves are installed according to the same principle. 41
Installation Installing the glueing socket and distance sleeve 1 Apply glue around the front outside part of the ADA- LF-DN 20 glueing socket. 2 Insert the glueing socket into the distance sleeve up to the stop while slightly rotating it, so that the glue is distributed evenly between the contact surfaces. 3 Allow the glue to harden. 4 Apply PVC glue around the front outside part of the distance sleeve. 5 Insert the distance sleeve into the T-piece while slightly rotating it, so that the glue is distributed evenly between the contact surfaces. 6 Allow the glue to harden. 7 Wrap the thread of the LRD 325 with Teflon sealing tape. 8 Tightly screw the measuring cell into the glueing socket. 42
Maintenance, cleaning, disposal 4 Maintenance, cleaning, disposal Warning Contact with the measuring solution can endanger the user! Take protective measures suitable for the kind of measuring solution (protective clothes, eye protectors etc.). Caution For all maintenance work, disconnect the conductivity measuring cell from the instrument! 4.1 Aging of the measuring cell Normally, the conductivity measuring cell does not age. Special measuring media (as for example strong acids and lyes) or too high temperatures considerably shorten the operational life time or cause damage. Failure caused by such measuring media and mechanical damage are not covered by the warranty. 43
Maintenance, cleaning, disposal 4.2 Cleaning Caution Especially before measuring low conductivity values, we recommend to clean the measuring cell thoroughly. Before measuring, thoroughly rinse the conductivity measuring cell with deionized water. Water-soluble substances Cleaning material Deionized water Reaction time at room temperature any Grease and oil Warm water and household dishwashing solution; In case of heavy contamination: methylated spirit any 5 minutes maximum Lime and hydroxide coatings Acetic acid (10 %) any 4.3 Disposal We recommend to dispose of the measuring cell as electronic waste. 44
Recommended accessories 5 Recommended accessories Stainless steel adaptor sockets Model Order no. EST-LRD 303209 ADA-3/4 NPT 303201 ADA-G 1 Zoll 303202 PVC glueing socket Model Order no. ADA-LF-DN 20 303203 PVC distance sleeves Model Order no. ADA-DN 25 303204 ADA-DN 32 303205 ADA-DN 40 303206 ADA-DN 50 303207 45
Recommended accessories 46
What to do if... 6 What to do if... No temperature displayed Cause Defective temperature sensor Conductivity measuring cell not connected Incorrect instrument setting Remedy Send the conductivity measuring cell to WTW Connect the conductivity measuring cell Correct the instrument setting Measuring does not work Cause Conductivity measuring cell not connected Incorrect instrument setting Remedy Connect the conductivity measuring cell Correct the instrument setting Measured values are not plausible Cause Conductivity measuring cell not connected Conductivity measuring cell is heavily contaminated Cable or electrodes are damaged Incorrect instrument setting Measuring range exceeded Remedy Connect the conductivity measuring cell Clean the conductivity measuring cell Send the conductivity measuring cell to WTW Correct the instrument setting Select other measuring range 47
What to do if... 48
Technical data 7 Technical data 7.1 General features Electrodes Number of electrodes 4 Electrode material Graphite Material Housing Stainless steel, 1.4571 Front part of the probe Epoxy resin, black Cable screw joint Brass, nickel-plated Cable PUR Dimensions Length that can be screwed in Immersion depth Pressure resistance Shaft diameter 15.3 mm Length up to screw joint 113.4 mm Diameter of connection head 24.8 mm Hexagon Wrench size 22 Total probe length 180 mm Cable lengths 1.5 m, 3 m and 7 m Thread 1/2" NPT 61 mm min. 36 mm 10 bar (20 C) 49
Technical data Connection Cable, plug Measuring cell: - Screw-in length - Cable screw joint Protection class IP65 when connected Protection class IP 68 10 bar (20 C) Protection class IP 67 2 bar (20 C) Cell constant K = 0.475 cm -1 ± 1.5 % Application range 1 µs/cm... 2 S/cm (resolution according to measuring instrument) Temperature measurement Storing medium Thermistor type Integrated NTC (30 kohm / 25 C) Thermistor housing material Air Graphite Operating range -5.. +100 C Thermistor response time Probe accuracy t 99 < 20 s ± 0.2 K 50
Technical data 7.2 Electrical data Wiring diagram Probe 7 pin plug with cable Screen Thermistor NTC Thermistor NTC Current electrode (ring) Potential electrode Potential electrode Current electrode (ring) Pin assignment Top view of the plug Pin Assignment Voltage Max. current 1 2 3 4 5 6 7 Potential electrode (u2) Potential electrode (u1) Current electrode (i1) Screen NTC (30 kohm) Current electrode (i2) NTC (30 kohm) < 1.3 V < 1.3 V < 1.3 V --- < 4.5 V < 1.3 V < 4.5 V < 0.5 ma < 0.5 ma < 0.5 ma --- < 0.5 ma < 0.5 ma < 0.5 ma 51
Technical data Caution All voltages must be protective low voltages or safety extra low voltages without shock-hazard according to - IEC 1010 or UL3101. All currents to the probe must not exceed 8 A even in case of a short-circuit. 52