Instructions

3. Measure the temperature with the 2626 probe and compare it with the
temperature read from the reference thermometer in the chamber to ob
-
tain the temperature measurement error:
Terror Tn T Tn Treference Tn() () ()=−2626
or
Measure the relative humidity using the 2626 probe and compare it with
the relative humidity read from the chamber to obtain the humidity mea
-
surement error:
RHerror RHn RH RHn RHchamber RHn() () ()=−2626
9.5 Temperature and Humidity Adjustments
Adjustments to the 2626-x calibration parameters are required when measure-
ment errors are excessive or outside of the specification. The calibration pa-
rameters can be accessed using the SENSOR CAL function in the CHANNEL
menu. The password is required to change the parameters. Calculation of new
calibration parameters requires that the measurement errors first be obtained
according to the procedure above in section Temperature and Humidity Mea-
surement Errors.AftertheTemperature and Humidity Adjustments proce-
dure is completed, perform the Temperature and Humidity Measurement
Errors procedure again to verify the calibration.
1.
Calculate the adjustment ΔTSL to the temperature slope parameter TSL,
and the new temperature slope parameter:
ΔTSL
Terror T Terror T
TT
=− ° ×
−
−
10
31
31
C
[() ()]
()
TSL TSL TSL′= +Δ
2. Calculate the slope-adjusted temperature errors:
Terror Tn Terror Tn TSL
Tn
() ()
()
′= + ×
−°
°
Δ
25
10
C
C
3. Calculate the median slope-adjusted temperature error, the adjustment
ΔTOS to the temperature offset parameter TOS, and the new temperature
offset parameter:
Tmedian
Terror T Terror T
′=
′+ ′() ()32
2
ΔTOS Tmedian=− ′
TOS TOS TOS′= +Δ
4.
Calculate the adjustment ΔHSL to the humidity slope parameter HSL,
and the new humidity slope parameter:
135
9 Calibration Procedure
Temperature and Humidity Adjustments