Grant Instruments TXF200 Operating Manual - Manual (Page 34)

30424 V6 TX150 & TXF200
Page 33 Operating Manual
www.grantinstruments.com
5.4 Completing a calibration
The TX150 & TXF200 allow up to five temperature points to be calibrated. The calibration
menu can be accessed by simultaneously pressing the F and S buttons for 3 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.
Two factory defined calibration points (20˚C and 70˚C) already exist and are displayed in
the calibrate probe menu, these may be recalibrated if required and up to a further three
calibration points added. 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.
The TX150/TXF200 calculates the temperature at any point using calculated values that
pass through each calibration point. This ensures precision at all critical experimental
temperatures throughout the range in use. In the example below, 4 calibration points
have been used.
Calibration points must be a minimum of 5˚C apart and there must be at least 20˚C
between the highest and lowest points. Any points added that do not match these criteria
will not be accepted by the unit.
Once set, calibration points can be changed or deleted but a minimum of 2 points must
remain.
Prior to calibration, ensure the probe type to be calibrated is selected, (internal or
external); the bath is set to the desired temperature and has been stable at the
temperature for at least 5 minutes.
User recorded
Temperature
Measured
Temperature
t3 t4 t2 t1
T4
T3
T2
T1