STARTER 2000 Bench ph Meter Instruction Manual

Transcription

1 STARTER 2000 Bench ph Meter Instruction Manual

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3 Table of Contents 1 Introduction Safety measures Display and controls Installation Package contents Installing the electrode arm STARTER 2000 operation Calibration Buffer group Performing calibration Sample measurement ph measurement mv measurement Setup Endpoint mode Manual temperature compensation Maintenance Error message Meter maintenance Electrode maintenance Specifications

4 1 Introduction Thank you for purchasing this high quality OHAUS meter. Please read the manual completely before using the STARTER 2000 bench ph meter to avoid incorrect operation. The STARTER 2000 has an excellent price/performance ratio and is designed with many useful features. You will find much helpful functionality in the meter. A few of the many existing features are: White backlit liquid crystal screen which make display more clear Auto endpoint which could help users freeze the stable reading value The flexible built-in electrode holder Ohaus renowned user friendly software 1.1 Safety measures Measures for your protection Never work in an environment subject to explosion hazards! The housing of the instrument is not gas tight (explosion hazard due to spark formation, corrosion caused by the ingress of gases) When using chemicals and solvents, comply with the instructions of the producer and the general lab safety rules Measures for operational safety Do not unscrew the two halves of the housing Dry off any liquid spills immediately! The instrument is not watertight Exclude the following environmental influences: - Powerful vibrations - Direct sunlight - Atmospheric humidity greater than 80% - Corrosive gases present - Temperatures below 5 C and above 40 C - Powerful electric or magnetic fields 2

5 1.2 Display and controls Displays Electrode condition catoon face Slope: more than 95% and offset: ± (0-60) mv Electrode is in very good condition 2 Calibration icon 3 Endpoint stability / Auto endpoint 4 Error index 5 Manual temperature compensation 6 ph/mv reading Slope: 90-95% or offset: ± (0-60) mv Electrode is in good condition Slope: less than 90% or offset: ± (>60) mv Electrode needs cleaning or is defective 3

6 Controls Button Press & release Press & hold for 3 seconds - Start measurement - Back to measurement screen - Turn auto endpoint on / off, - Start calibration - Meter on/off - Increase value during manual temperature setting - Decrease value during manual temperature setting - Switch between ph and mv measuring modes 4

7 2 Installation Carefully unpack the meter, insert the right adapter clip into the power adapter slot. 2.1 Package contents The model ST2000-B has the following items ST2000-B Units STARTER 2000 meter 1 Built-in electrode holder 1 ph Buffer Power Set (4.01, 7.00, 10.01) 1 set In addition to ST2000-B package content, the model ST2000 package also includes the following: ST210 2-in-1 ph electrode Installing the electrode arm Install the built-in electrode holder on the meter. Adjust the tension knob as required. 5

8 3 STARTER 2000 operation 3.1 Calibration Buffer group The Starter 2000 ph meter allows you to perform 1-, or 2 point calibrations. The calibration buffer group is predefined in the meter, the buffers are automatically recognized and displayed during calibration (auto buffer recognition). The predefined group is: Buffer (at 25 C) Starter 2000 ph meters manually correct for the temperature dependence of the buffer ph using the values given in the table (see 4.2, Manual temperature compensation). Buffer group related to the temperature (ref. 25 C) Temp ph4.01 ph7.00 ph Performing calibration Firstly set the MTC temperature (see 4.2), then place the electrode in a calibration buffer and press Cal. Cal 1 is blinking during calibration. After immersing the electrode into the buffer, stir and wait for 1 minute, then press Cal to finish 1 point calibration, the relevant buffer value is displayed and stored; now the Cal 2 is blinking, you have 2 choices now: 1) press Read to exit calibration and return to the sample measurement. Or 2) perform the second point calibration, immerse the electrode into the second buffer, stir and wait for 1 minute, then press Cal to finish 2 point calibration and return to sample measurement automatically. The electrode condition icon will be displayed on the screen. Note: With the 1-point calibration only the offset is adjusted. If the sensor was previously calibrated with multi-point calibration the previously stored slope will remain. Otherwise theoretical 100% slope ( mv / ph) will be used. To ensure the most accurate ph measurement, you should perform a calibration once a day. 6

9 3.2 Sample measurement ph measurement Place the electrode in the sample and press Read to start the measurement. The automatic endpoint is the default setting of the meter. When the signal has stabilized, the sample reading freezes, the endpoint stability and auto endpoint icons freeze on the display. By pressing and holding Read, you can switch between the auto and manual endpoint modes. In manually endpoint the endpoint stability icon will show on the display when the meter judge the signal has stabilized, the reading is not freezing, the meter is still on measurement mv measurement To switch to mv mode, press ph/mv. To perform an mv measurement, follow the same procedure as for ph measurement. 4 Setup 4.1 Endpoint mode The automatic endpoint is the default setting of the meter. By pressing and holding Read, you can switch between the auto and manual endpoint modes. In auto endpoint mode, press Read to start the measurement, then the meter judge the endpoint automatically and lock the endpoint reading. In manually endpoint mode, you should confirm the final reading result by your observation, the sample reading will not freeze, the endpoint stability icon means reading is stable according to the meter judgment. 4.2 Manual temperature compensation In the sample measurement mode, use up or down buttons to increase or decrease the value to the temperature of the sample. Press Read to confirm the setting. The default setting is 25 C. 7

10 5 Maintenance 5.1 Error message Error 1 Error 2 Error 3 Error 4 Error 5 Error 6 Measured ph value out of range ( 14.5pH or -0.5pH ) Measured potential value out of range ( 1700mV or mV ) Offset out of range ( offset -80mV or offset 80mV ) Slope out of range ( slope 110% or 80%) Electrode potential out of range when calibration. ( 240mV ) Electrode potential out of range when calibration. ( -240mV ) Check if the electrode is properly connected to the STARTER 2000 meter, or the electrode is damaged. Check if the electrode is properly connected to the STARTER 2000 meter. Check if the buffer is fresh, or the electrode needs to be recalibrated or replaced. Check if the buffer is fresh, or the electrode needs to be recalibrated or replaced. Check if the buffer is fresh, or the electrode needs to be recalibrated or replaced. Check if the buffer is fresh, or the electrode needs to be recalibrated or replaced. 5.2 Meter maintenance The STARTER 2000 does not require any maintenance other than occasional wipe with a damp cloth. The housing is made of acrylonitrile butadiene styrene (ABS). This material is attacked by some organic solvents, such as toluene, xylene and methyl ethyl ketone (MEK). Any spillage should be immediately wiped off. 5.3 Electrode maintenance Make sure the electrode is filled with electrolyte solution. Always store the electrode according to the manufacturer s instructions and do not allow it to dry out. If the electrode response becomes sluggish or the slope is not good enough, try: 1. Soak the electrode in 0.1M HCl overnight 2. For fat or oil build-up, degrease the membrane with cotton wool soaked in either acetone or a soap solution After electrode treatment, a new calibration should be performed. If the electrode slope is still not satisfactory, the electrode might need to be replaced. 8

11 6 Specifications Measuring range Resolution Error limits Calibration Power supply Size/weight Display Input Temperature-compensation Housing STARTER ph mv 0.01 ph 1 mv 0.1 C ± 0.05 ph 1%FS mv 2 points 1 predefined buffer group (4.01, 7.00, 10.01) 9 V DC, V/50-60Hz Approximately 195 W x 150 D x 60 H mm / 0.55 kg White backlit Liquid crystal BNC, impedance > 5 * 10e+11 Ω Manual Temperature Compensation ABS 9

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