Servicing
Optical Bench Temperature Calibration
Thermo Fisher Scientific
Model 49
i
Primary Standard Instruction Manual
6-17
6. Press
>
to return to the input channels display and repeat
Steps 3-5 to calibrate other input channels to the source voltage as
necessary.
Optical Bench
Temperature
Calibration
Use the following procedure to calibrate the optical bench temperature.
Equipment Required:
Calibrated thermometer or 10K ±1% Resistor
1. Remove the instrument cover.
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 (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 Bench Temp screen appears.
WARNING
The service procedures in this manual are restricted to qualified
service representatives.
If the equipment is operated in a manner not specified by the manufacturer,
the protection provided by the equipment may be impaired.
Equipment Damage
Some internal components can be damaged by small
amounts of static electricity. A properly grounded antistatic wrist strap must
be worn while handling any internal component.