Problem Solution
While attempting to measure re
-
sistance the display shows an in
-
correct value.
Poor or incorrect connection of the probe. A common mistake is to
connect the wires of the probe to the wrong terminals. Check the wir
-
ing carefully (see Figure 6).
Open, shorted, or damaged sensor or lead wires. Check the resis
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tance across the sensor using a handheld DMM. Also check the resis
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tance between common pairs of leads. Check to make sure there is
no conductivity between any of the leads and the probe sheath. Use a
good-quality sensor to avoid errors caused by drift, hysteresis, or in
-
sulation leakage.
Stem conduction error. Make sure the stem of the probe is im
-
mersed in the medium with adequate depth and a tight fit.
Electrical interference. Intense radio-frequency radiation near the
1521 or the probe can induce noise into the measurement circuits re
-
sulting in erratic readings. Try eliminating the source of interference or
moving the 1521 to a different location. A well-grounded, shielded ca
-
ble should be used for the probe.
Memory Check Error Memory Error.
A non-critical parameter is corrupt in memory. The non-critical
praameters are Units, Rate, Resolution, Filter, and serial port settings.
Press any key and the display reads “Check Settings”. Press any key
again to resume normal operation. Check your current settings for the
specific parameters that were set.
Memory Recover X.
A critical parameter is corrupt and the 1521 can recover the correct
value for that parameter. The critical parameters are CAL1, CAL2,
Passcode, Meter Due Date, Meter Cal Date, and Serial Number.
Press any key and the display reads “Check Settings”. Press any key
again to resume normal operation. Also, check non-critical settings as
in the Memory Error above. The number following the message is
used by authorized technicians.
Memory Invalid!
A critical parameter is corrupt and the 1521 cannot recover the cor
-
rect value for the parameter. The critical parameters are CAL1, CAL2,
Passcode, Meter Due Date, Meter Cal Date, and Serial Number.
Press any key and the display reads “Contact Factory”. Contact an
Authorized Service Center (see Section 1.3) for assistance in guiding
you through the process of reentering critical parameters.
Note: The parameters stored in the INFO-CON, Probe Wires, Probe
Type, Probe Parameters, are not checked by the meter during mem
-
ory testing.
11.2 CE Comments
11.2.1 EMC Directive
Hart Scientific’s equipment has been tested to meet the European Electromag
-
netic Compatibility Directive (EMC Directive, 89/336/EEC). The Declaration
of Conformity for your instrument lists the specific standards to which the unit
was tested.
1521 Handheld Thermometer Readout
User’s Guide
48
