Chapter 4
pH, pH/ISE and pH/LogR Measurement Modules
Thermo Scientific
Orion Versa Star Pro Meter User Manual
57
Temperature Calibration
Versa Star Pro meters have a relative temperature accuracy of ±0.1°C. ATC temperature
probes have varying relative accuracies, usually ±0.5°C to ±2°C. Use the temperature
calibration function only when necessary. Since the temperature offset calculated during the
calibration is applied to all future temperature measurements, recalibrate the temperature if a
different ATC temperature probe is used.
ATC Probe Temperature Calibration
ATC (Automatic Temperature Compensation) probes are defined as both separate temperature
probes and those built into electrodes. A temperature calibration can be performed for individual
ATC probes or simultaneously for all ATC probes connected to the meter. Prepare and connect
all ATC probes to be calibrated to the appropriate module inputs on the selected channels.
1.
In the measurement mode, press the setup key.
2.
Press the
,
,
or
key to highlight Channel 1, Channel 2, Channel 3 or Channel 4
and press the f3 (Select) key.
a.
Select the appropriate channel number that the ATC probe of interest is connected.
3.
Press the
or
key to highlight Temperature and press the f3 (Select) key.
4.
Press the
or
key to highlight Temperature Input and press the
or
key to
highlight an ATC probe (i.e. Ch2-ATC) as the temperature source for the selected channel.
5.
Press the
or
key to highlight Temperature Cal and press the
or
key to highlight
the individual ATC probe (i.e. Ch2-ATC) or All ATC and press the f3 (Select) key.
6.
Place the ATC probes into a solution with a known, stable temperature. It is recommended
that two NIST-traceable thermometers be used to measure and verify the temperature.
7.
Press the f3 (Edit) key, use the numeric keypad to enter the temperature of the solution
and press the f2 (Accept) key to save the temperature value and update the offset.
8.
If applicable, press the
or
key to highlight the reference temperature of the next ATC
probe and repeat steps 6-7 for each ATC probe connected to the meter.
9.
Once all ATC probes are calibrated, press the f1 (Back) key to exit the calibration.
