Thermo Scientific 42i Instruction Manual page 219

Ambient Temperature
Calibration
Thermo Fisher Scientific
Use the following procedure to calibrate the ambient internal temperature
for the instrument.
Equipment Required:
Calibrated thermometer or 10K ±1% Resistor
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 ground antistatic wrist strap must
be worn while handling any internal component.
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 (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 Temperature Calibration > and press
The Calibrate Ambient Temperature screen appears.
Note If Service Mode is not displayed, refer to
Mode" on page 7-4 , then return to the beginning of this step.
▲
(Figure 7–2).
to scroll to Service > press
Servicing
Ambient Temperature Calibration
▲
.
"Accessing the Service
▲
Model 42i Instruction Manual
>
7-35