Fluke 5020A, User Manual

Page: 129 / 142

Calibration Procedure
Temperature and Humidity Adjustments
7
7-5
that the measurement errors first be obtained according to the procedure above in section
Temperature and Humidity Measurement Errors. After the Temperature and Humidity
Adjustments procedure is completed, perform the Temperature and Humidity
Measurement Errors procedure again to verify the calibration.
1. Calculate the adjustment
∆
TSL to the temperature slope parameter TSL, and the
new temperature slope parameter:
[ ]
( )
1 3
) 1 ( ) 3 (
10
T T
T Terror T Terror
C TSL
−
−
× ° − = ∆
TSL TSL L TS
∆ + =
′
2. Calculate the slope-adjusted temperature errors:
( )
C
C Tn
TSL Tn Terror Tn Terror
°
° −
× ∆ + =
′
10
25
) ( ) (
3. Calculate the median slope-adjusted temperature error, the adjustment
∆
TOS to
the temperature offset parameter TOS, and the new temperature offset parameter:
( ) ( )
2
2 3
′
+
′
=
′
T Terror T Terror
n Tmedia
4. Calculate the adjustment
∆
HSL to the humidity slope parameter HSL, and the
new humidity slope parameter:
( ) ( )
[ ]
( )
1 3
2 3
% 25
RH RH
RH RHerror RH RHerror
HSL
−
−
× − =
HSL HSL L HS
∆ + =
′
5. Calculate the slope-adjusted humidity errors:
( ) ( )
( )
% 25
% 45
Re
−
× ∆ + =
′
RHn
HSL RHn rror H RHn RHerror
6. Calculate the median slope-adjusted humidity error, the adjustment
∆
HOS to the
humidity offset parameter ∆ HOS, and the new humidity offset parameter:
( ) ( )
2
2 3




′
+
′
=
′
RH THerror RH RHerror
n RHmedia
n RHmedia HOS
′
− = ∆
HOS HOS S HO
∆ + =
′
7. Enter the new values for TOS (TOS ′ ), TSL (TSL ′ ), HOS (HOS ′ ), and HSL
(HSL ′ ) into the thermo-hygrometer. Also set the DATE to the current date and
set the DUE date for the next calibration. If a power-on warning message is
desired when the DUE date expires, set ALERT to ON. Do not change the serial
number. Press ENTER when prompted to write the new values to the sensor.