02/2014
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Example 2:
TRJ-value
in the online-mask
=
24.10 °C
Measured cold junction temperature
=
25.00 °C
--------------------------------
ΔT = (24,1 - 25,0) °C
=
-0.90 °C
Load resistance = 0.39 Ω/°C x (-0.9) °C
=
-0.35
Ω
The TRJ calibration has to be carried out while using an external and an internal Pt 100
sensor.
A filter of the 1
st
order is parameterized by means of the filter time of up to 999 seconds for the temperature
reference junction (TRJ). The greater the filter time, the greater the damping of temperature fluctuations.
6.1.11. Calibration
Calibrate input
Resistance, Current and Voltage
After reading in the set of parameters from the MTP200, you have to activate the resistance measurement
input for the 2-wire or 4-wire circuit as the active input by using the jumpers (see section 10.4 Measurement
inputs).
Resistance input for 2- or 4-wire-circuit:
The input is defined as a 2-wire or 4-wire circuit using the jumpers JP8/JP9, and the calibration is defined
accordingly on this basis. If the input configuration is changed later, the calibration should be repeated for
maximum accuracy. For the 2-point calibration within the characteristic curve range you can freely select the
calibration points, but we always recommend using the required measuring range for the calibration range.
The calibration procedure is the same as for a thermocouple input (10.1.10).
Current input:
A bi-directional mA signal can be measured with the mA input at KL13/14. The calibration points can thus be
placed in a range from -20 mA to +20 mA. The 2-point calibration takes place as already described.
Voltage input:
A bi-directional V signal can be measured with the V input at KL15/14. The 2 calibration points, placed in a
range from -10 V to +10 V, are recorded in the same way as previously documented.
