Error Situations - BEAMEX MC5-IS User Manual

Error situations

92
Advanced Operation and Configuration
The easiest way to avoid errors in thermocouple measurement
and simulation is to carefully check the used wiring and the Refer-
ence Junction mode. The following table describes the typical er-
ror situations and possible causes/corrections when working with
thermocouples:
PROBLEM
MC5-IS (or the
instrument under test
when simulating
thermovoltages)
measures the
temperature/millivolt
signal, but the displayed
temperature reading is all
wrong.
(The error may vary from
0 to about ±50°C
depending on the type of
the error)
MC5-IS (or the
instrument under test)
displays random readings
during thermocouple
measurement.
MC5-IS displays unstable
readings during
thermocouple simulation.
CAUSE
• The thermocouple type selected in
MC5-IS does not correspond with the
used thermocouple.
• The selected Reference Junction
mode is not in accordance with the
used wiring.
• Extension or compensation cable type
or connections are incorrect.
• The polarity of the cables are
incorrect.
• Incorrect connections.
• The wiring is broken.
• Interference from a mobile phone or a
radio transmitter affects the
measurement.
• The instrument under calibration uses
voltage pulses to detect open sensor.
When MC5-IS detects these pulses, it
tries to compensate for them, which
causes the unstable output. Prevent
these pulses for the time of
calibration. Refer to the service
manual of the instrument under
calibration on how to prevent these
open sensor detection pulses.