Operator's Manual
Issue 14 / Mar 2016
MercuryiPS
©2016 Oxford Instruments NanoScience. All rights reserved.
Page 69
Soft edge
This is similar to bipolar excitation, except the current ramps between the positive and
negative values. The current is maintained at a stable value between the ramps to allow a
measurement to be taken. Soft-edge excitation might be used to reduce electrical
interference produced by fast-changing currents.
6.5.6 Calibration for different sensors
The iPS uses calibration tables to store calibration data for different sensor types. The user can
also create a new calibration file for a specific sensor. Calibration tables can be saved as files.
The MercuryiPS accepts calibration files with .dat or .prn extensions.
A calibration file contains a number of discrete data pairs, each mapping a sensor reading on
to a temperature value. The first column is the output (eg. temperature, pressure) and the
second column is the input (eg. resistance, voltage, current).
By default, values are assumed to be in SI units. However, a header for each column may be
used to define the units. Both columns must have valid units or both will be ignored
completely. Other headers are also ignored.
.dat files are space separated. Tabs or multiple spaces are acceptable.
Numbers may be expressed in regular (0.0134) or scientific (1.34e-2) notation.
Linear interpolation is used to provide calibration at intermediate values.
There is no theoretical limit to the number of sets of data points, but a practical limit is about
1000.
The iPS calculates set point limits and sensor limits from the chosen calibration file.
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