Power Supply; Changing Chart Paper; Calibration Adjustment - Thermo Scientific ULT185-5-A Instruction Manual

8.2 Power Supply

8.3 Changing Chart
8.4 Calibration
Adjustment
Thermo Scientific Benchtop Ultra-Low Temperature Freezers
The recorder normally uses AC power when the system is operating. If AC
power fails, the LED indicator flashes to alert you to a power failure. The
recorder continues sensing cabinet temperature and the chart continues
turning for approximately 24 hours with back-up power provided by the
nine-volt battery.
The LED indicator glows continuously when main power is functioning
and the battery is charged.
When the battery is low, the LED flashes to indicate that the battery needs
to be charged.
To change the chart paper, complete the following steps:
Paper
1. Locate the pressure sensitive buttons at the front, upper left of the
recorder panel.
2. Press and hold the Change Chart button (#3) for one second.The pen
will move off the scale.
3. Unscrew the center nut, remove the old chart paper, and install new
chart paper. Carefully align the day and time with the reference mark 
(a small groove on the left side of the recorder panel).
4. Replace the center nut and make sure it is hand tightened. Press the
Change Chart button again to resume temperature recording.
This recorder has been accurately calibrated at the factory and retains
calibration even during power interruptions. If required however,
adjustments can be made as follows:
1. Run the unit continuously at the control setpoint temperature.
Continue steady operation for at least two hours to provide adequate
time for recorder response.
2. Measure cabinet center temperature with a calibrated temperature monitor.
3. Compare the recorder temperature to the measured cabinet
temperature. If necessary, adjust recorder by pressing the left (#1) and
right (#2) chart buttons.
Note The stylus does not begin to move until the button is held for five seconds.
Chart Recorders (Optional)
Installation and Operation Manual
13