Thermo Scientific 146i, Instruction Manual

Page: 225 / 340

Servicing
Photometer Temperature Calibration (Photometer option)
Thermo Fisher Scientific Model 146 i Instruction Manual 7-37
3. Remove the thermistor and replace it with the new thermistor.
4. Connect the thermistor electrical connection.
Photometer
Temperature
Calibration
(Photometer option)
Use the following procedure to calibrate the photometer temperature.
Equipment Required:
Calibrated thermometer or 10K ±1% Resistor
1. Remove the instrument cover.
2. Tape the thermistor ( Figure 7-12 ) 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.