Millipore System Documentation Set
190 Operating and Maintenance Manual Publication XITXSP121 P Rev.A
TEMPERATURE SENSOR CALIBRATION
The temperature sensor is calibrated against an external referee temperature sensor. The
referee gauge should be traceable to the NIST (National Institute of Standards Testing) or
equivalent. The calibration is conducted with an automated procedure that prompts the user
through the calibration process.
Calibration Criteria
Table 21: Temperature Sensor Specifications
Sensor Accuracy Specification
Internal temp sensor
+/- 0.5 °C (+/- .9°F)
External temp sensor
+/- 0.5 °C (+/- .9°F)
Calibration Curve Fits
Each of the transducers has a non-linear relationship vs. a referee temperature sensor.
The calibration procedure compares the referee value against the internal temperature sensor
readings at three points across the operating range of the sensor (4–60 °C). A regression
analysis is performed to determine a line of best fit and a measure of the quality of the
calculated regression (R
2
).
Calibration Adjustment Decisions:
The temperature sensor is only adjusted (against the manufacturer’s specifications) when
necessary. (Adjustments are made by changing the calibration coefficients.)
Calibration adjustment decisions are determined by the R
2
value
in Table 22.
Table 22: Calibration adjustment decisions (c)
R
2
Value Decision Action
< 1.82 x
variance
The sensor is
considered good.
No adjustments are made to the
calibration coefficients.
>1.82 x
variance
A t test on residuals
is conducted on the
calibration
coefficients.
If the t test fails, the calibration
coefficients (for slope & the zero
intercept) are automatically
adjusted.
If the t test passes, no adjustment is
made to the coefficients. The unit is
locked out from performing tests.
To Next Page
Loading...