OxyTechw² GAL Instruction Manual
9
Calibration and Testing
9.1 Temperature
9.1.1 Overview
As already mentioned the OxyTech2² GAL sensor has two integral temperature measurements. The
first measurement is not displayed and is used solely to compensate for temperature fluctuations in the
measurement solution across the membrane. It produces a stabilised millivolt electrical output
proportional to the oxygen partial pressure it senses. The other temperature measurement is
transmitted back to the 7300 monitor and is used to:
1) Display temperature.
2) Compensate for changes in saturation reading due to temperature, by referencing the reading to a fixed
temperature value.
3) Calculating the solubility of the solution in mg/l.
Once the temperature has been calibrated there should be no reason to re-calibrate as the
measurement is inherently stable and will not change over time. The accuracy of the reading depends
on the sensor head equilibrating with temperature. Thus the sensor element buried within the body of
the sensor becomes representative of the true temperature in the surrounding environment.
The temperatures integrity can be checked at any time by comparing it with a known temperature
reference after a period of temperature equilibration. If for any reason the temperature is deemed to be
inaccurate or needs to be different from the settings as carried out in the factory, then the following
procedure may be applied.
9.1.2 Calibrate Temperature
From the 7300w² Monitor, navigate to the Calibration menu as follows:
1. Ensure that the sensor head, whether in or out of solution has been
in a constant temperature environment for at least 20 minutes
before commencing this operation. Ensure that the reference
measurement tool, e.g. thermometer is also suitably temperature
equilibrated.
2. Press
to show the “MAIN MENU”.
3. Select “MEASUREMENT CONFIG” by pressing
and press
.
4. Select “TEMPERATURE” by pressing
and press
.
5. Select “SET CAL” by pressing
press
.
6. The sensor information screen will be displayed. Press
to move
on.
224083IM-Issue 04 20/03/2018
Page 19 of 28
MEASUREMENT CONFIG
Measurement Status
Add Measurement
M:01 Dissolved Oxygen (S:01)
M:02 Dissolved Oxygen (S:01)
M:03 Temperature (S:01)
M:04 Dissolved Oxygen (S:01)
M:03 CONFIG
M:03 Info
M:03 Set Cal (25.0 ºC)
M:03 Remove
M:03 Display Position
M:03 Restore Defaults
M:03 SET CAL (25.0 ºC)
CALIBRATE MEASUREMENT
M:03 temperature
S:01 OxyTechw
2
GAL
SN: 400001
Last Calibrated: 01/01/1970 00:00:00
By:
Press OK to contiue or MENU to Exit