TB 9-5855-1890-24
NOTE
V/ C, into observed
multimeter no. 1 indication. The result equals differential
temperature.
b. Adjustments
(1) Open access hatch on shroud and remove cover plate from TI temperature controller.
(2) Set offset voltage switch to ALIGN.
(3) Adjust offset voltage potentiometer R4 (fig. 1) for an indication change of 0.1 V dc
on multimeter no. 2.
NOTE
If T is less than 4.05 oC, decrease offset voltage; if
T is
greater than 4.95 oC, increase offset voltage.
NOTE
As temperature indication nears in-tolerance condition, it may
be necessary to adjust offset voltage in 0.05 V dc increments.
(4) Set offset voltage switch to ON.
(5) Replace temperature controller cover plate, close shroud access hatch, and allow
15 minutes for temperature stabilization.
(6) Observe and record indication on multimeter no. 1.
(7) Using differential thermocouple set calibration data and indication on
multimeter no. 1, calculate the temperature difference indication.
(8) Repeat (1) through (7) above as required to produce a temperature difference
indication between 4.35 oC and 4.65 oC.
(9) Set power switch to OFF, but do not disconnect test setup. Allow TI to cool for
15 minutes.
(10) Set voltage offset switch to ALIGN.
(11) When multimeter no. 1 indicates 0 l0 V, set power switch to ON and
immediately observe multimeter no. 2 indication and record as Vo (new).
(12) Set power switch to OFF.
(13) Set voltage offset switch to ON.
a. Annotate value of Vo (new) on offset voltage label located on TI temperature
controller (R).
NOTE
If TI has not required adjustment, record previous offset
voltage as Vo (new).
b. Deenergize and disconnect all equipment and reinstall protective cover on TI.