Problem Solution
Whileattempting to measure re-
sistancethe display shows an in-
correctvalue.
Pooror incorrect connection of the probe. A common mistake is to
connectthe wires of the probe to the wrong terminals. Check the wir-
ingcarefully (see Figure 6).
Open,shorted, or damaged sensor or lead wires. Check the resis-
tanceacross the sensor using a handheld DMM. Also check the resis-
tancebetween common pairs of leads. Check to make sure there is
noconductivity between any of the leads and the probe sheath. Use a
good-qualitysensor to avoid errors caused by drift, hysteresis, or in-
sulationleakage.
Stemconduction error. Make sure the stem of the probe is im-
mersedin the medium with adequate depth and a tight fit.
Electricalinterference. Intense radio-frequency radiation near the
1521or the probe can induce noise into the measurement circuits re-
sultingin erratic readings. Try eliminating the source of interference or
movingthe 1521 to a different location. A well-grounded, shielded ca-
bleshould be used for the probe.
MemoryChe ck Error MemoryE rror.
Anon-critical parameter is corrupt in memory. The non-critical
praametersare Units, Rate, Resolution, Filter, and serial port settings.
Pressany key and the display reads “Check Settings”. Press any key
againto resume normal operation. Check your current settings for the
specificparameters that were set.
MemoryRecover X.
Acritical parameter is corrupt and the 1521 can recover the correct
valuefor that parameter. The critical parameters are CAL1, CAL2,
Passcode,Meter Due Date, Meter Cal Date, and Serial Number.
Pressany key and the display reads “Check Settings”. Press any key
againto resume normal operation. Also, check non-critical settings as
inthe Memory Error above. The number following the message is
usedby authorized technicians.
MemoryInva lid!
Acritical parameter is corrupt and the 1521 cannot recover the cor-
rectvalue for the parameter. Thecritical parameters are CAL1, CAL2,
Passcode,Meter Due Date, Meter Cal Date, and Serial Number.
Pressany key and the display reads “Contact Factory”. Contact an
AuthorizedService Center (see Section 1.3) for assistance in guiding
youthrough 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-
orytesting.
11.2 CE Comments

11.2.1 EMC Directive

Hart Scientific’sequipment has been tested to meet the European Electromag-

netic Compatibility Directive(EMC Directive, 89/336/EEC). The Declaration

of Conformityfor yourinstrument lists the specific standards to which the unit

was tested.

1521 Handheld Thermometer Readout
User’s Guide
48