31
10 pH indicator
The instrument is in the measurement mode,
“Operating modes and states”, page 24.
Calibration
✱
Press the
+
(Cal) keys
The lower display shows “°C”.
If the decimal point flashes, manual temperature acquisition is configured.
✱
Immerse the pH electrode and, if needed, the temperature probe in the
buffer solution.
✱
Set the temperature of the buffer solution with the
or
keys.
✱
If the decimal point does not flash, then automatic temperature acquisition
is configured
✱
Wait until the temperature reading has stabilized.
✱
Press the
key.
The lower display shows “Cal1” with the decimal point flashing.
✱
When the pH value display has stabilized, set the displayed value to the
value of the reference buffer using the
or
keys.
✱
Press the
key.
The instrument stores the new zero.
The instrument is in the measurement mode again.
10.5 2-point calibration
You will need
- a buffer solution, pH 7, for example
- a buffer solution with a pH value that differs from the first buffer solution by
at least
2 pH, for instance pH 10.
Both buffer solutions must have the same temperature.
- a thermometer, if you want to use manual temperature compensation for
calibration.
- a Pt100 or Pt1000 temperature probe, if you want to calibrate with
automatic temperature compensation.
Initial condition
A pH combination electrode connected to the 2-wire transmitter that is
attached to the dTRANS Az 01, as well as a Pt100 or Pt1000 temperature
probe (if required),
Chapter 10.1 “pH measurement circuit”, page 28ff.
Select calibration procedure,
Chapter 10.3 “Preparation”, page 29ff.
The operating level is unlocked,
“Unlocking the levels”, page 27, (code word 0110)
The instrument is in the measurement mode, see “Operation / Basics /
Operating modes and states", page 20.
If, on completion of calibration, the instrument shows “Err” in the
temperature display,
Chapter 34.1 “Messages”, page 101ff.
PGM
PGM
PGM
