Ph Value / Orp Voltage; General Information - wtw pH/ION 340i Operating Manual

Operation
Preparatory activities
Temperature sensor
16
4.2

pH value / ORP voltage

4.2.1 General information

Perform the following preparatory activities when you want to measure:
1 Connect the pH electrode to the measuring instrument.
If necessary, press the <M> key repeatedly until the status dis-
play pH (pH measurement) or U (measurement of the ORP
voltage) appears.
2 Adjust the temperature of the buffer solutions or test solutions,
or measure the current temperature, if you measure without a
temperature sensor.
3 Calibrate or check the measuring instrument with the elec-
trode.
4 Using < > < >, toggle between the pH or mV measuring
modes.
Note
Incorrect calibration of pH electrodes leads to incorrect measured val-
ues. Calibrate regularly before measuring.
Warning
When connecting an earthed PC/printer, measurements cannot be per-
formed in earthed media as incorrect values would result. The RS232
interface is not galvanically isolated.
You can measure with or without a temperature sensor. If a tempera-
ture sensor is connected, it is indicated on the display by TP.
Note
The measuring instrument automatically recognizes the type of the
temperature sensor used. Therefore, you can connect temperature
sensors of the NTC30 or Pt1000 type.
The temperature measurement is absolutely essential for a reproduc-
ible pH measurement. If the measurement is made without a tempera-
ture sensor, proceed as follows:
1 Measure the current temperature of the test sample using a
thermometer.
2 Enter the temperature on the instrument: While pressing the
<RUN/ENTER> key, enter the temperature value of the test
sample with < > < >.
pH/ION 340i