Servicing
Input Board Replacement
7-36
Model 43i Trace Level-Enhanced Instruction Manual
Thermo Fisher Scientific
2.
Tape the thermistor (plugged into the measurement interface board) to
a calibrated thermometer
Note
Since the thermistors are interchangeable to an accuracy of ±0.2
°
C,
and have a value of 10K ohms at 25
°
C, an alternate procedure is to
connect an accurately known 10K resistor to the thermistor input (AMB
TEMP) on the measurement interface board, and enter the temperature
reading.
▲
A 1
°
C change corresponds to a ±5% change in resistance, thus this
alternative procedure can be quite accurate as a check; however, it clearly is
not NIST traceable.
▲
3.
From the Main Menu, press
to scroll to Service > press
>
to scroll to
Temperature Calibration
> and press
.
The Calibrate Ambient Temperature screen appears.
Note
If Service Mode is not displayed, refer to “Accessing the Service
Mode” in this chapter, then return to the beginning of this step.
▲
4.
Wait at least 10 seconds for the ambient reading to stabilize, use
and
to enter the known temperature, and
press
to save the temperature value.
5.
Install the cover.
Use the following procedure to replace the input board (
Figure 7–18
).
Equipment Required:
Input board
Philips screwdriver
1.
Disconnect the BNC signal cable and the ribbon cable.
2.
Loosen the two screws securing the bracket holding the input board to
the floor plate, slide the bracket towards the optical bench slightly, and
lift it off the base screws.
Input Board
Replacement
