Figure 6-8. RTD Model Calibration
pH/ Temperature Model – UWBT-PH
You need to calibrate for pH and the RTD temperature input. You can calibrate
the device using 4 different temperature engineering units: Fahrenheit, Kelvin,
Celsius and Rankine. Below example uses degrees Celsius as an Engineering
unit. In order to change the engineering units go to the settings screen, select
the engineering unit and click save all settings button. If there is no RTD sensor
connected to the device, please change the solution temperature in the settings
menu and save all changes to the device before you start calibration (default
solution temperature is 22.2 °C). The pH input is a two point calibration using a
pH electrode and two buffer solutions (4 and 10 pH) or DC mV source (177mV
and -177mV):
• Select the pH Low Set Point option. Place the pH electrode in the 4 pH
solution (or set the DC source to 177mV), wait for, at least, 1-minute for the
measurement to stabilize and enter 4 pH in the low pH set point text box. Press
the Calibrate button.
• Select the pH High Set Point option. Place the pH electrode in the 10 pH
solution (or set the DC source to -177mV), wait for, at least, 1-minute for the
measurement to stabilize and enter10 pH in the high pH point text box. Press
the Calibrate button.
You can calibrate the pH input for any other buffer solutions like 7 and 10 pH.
The calibration is not limited to only 4 & 10 pH values. For RTD temperature
calibration, use a precision decade box:
• Select the Low Set Point Temperature option. Set the decade box to 101
Ω
and
enter 3 °C in the low set point temperature text box. Press the Calibrate button.
• Select the High Set Point Temperature option. Set the decade box to 127
Ω
and enter 70°C in the high set point temperature text box. Press the Calibrate
button.
6-8
Software Instructions (PC App)
6
