Grant Instruments LTC2 - Manual (Page 15)

LTC2 30933 V2
Operating Manual Page 14
www.grantinstruments.com
Preset Set temperature range
t-1 37°C
t-2 56°C
t-3 72°C
5.2.9 Running a bath preset
1. Press the F button and rotate the dial until the display shows the correct preset.
2. Press the S button to select the preset.
3. Press the S button to set the bath to the preset temperature.
5.2.10 Completing a calibration
The LTC2 allows a two point calibration to be completed. The calibration menu can be
accessed by simultaneously pressing the F and S buttons for about 5 seconds.
The calibration temperatures are constrained by the temperature limits of the liquid type
setting. Calibration should be carried out using a traceable reference thermometer with
an accuracy of at least 0.1°C. This thermometer should be held securely in the centre of
the bath or vessel.
The calibration of the LTC2 is in two parts, a low temperature offset and a high
temperature offset. The high temperature calibration point must be at least 40°C higher
than the low temperature point.
Calibration points should be chosen to be at critical experimental temperatures where
accuracy is important or at the extremes of the working range of used temperatures.
If only the low temperature calibration point is set then the calibration will be performed
between this point and 100°C with the offset decreasingly linearly. If only the high
temperature calibration point is set then the calibration will be performed between 0°C
and this point with the offset decreasingly linearly.
If the thermometer value is entered before the unit is completely stable then the
calibration could be poor and liquid temperature readings will be incorrect. If the LTC2 is
not in accordance with the thermometer following calibration then it may not have been
successful and the unit should be reset.
Setting the low temperature offset
1. Adjust the set temperature to the required low temperature calibration point.
2. Allow the unit to stabilise for at least 5 minutes after a stable temperature condition
has been achieved.
3. Measure the liquid temperature by placing a reference thermometer into the centre of
the bath.
4. Press the F and S buttons simultaneously for approximately 5 seconds until “LCAL” is
shown.
5. Press the S button to select.
6. Use the main dial to update the display to show the temperature on the reference
thermometer.
7. Press the S button to store the temperature.
Press the F button to cancel the calibration.
8. Press the F button to return to the liquid temperature display.