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 7).
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
1522or the probe can induce noise into the measurement circuits re-
sultingin erratic readings. Try eliminating the source of interference or
movingthe 1522 to a different location. A well-grounded, shielded ca-
bleshould be used for the probe.
MemoryChe ck Error MemoryRecover X.
Acritical parameter (CAL1, CAL2, or Passcode) is corrupt and the in-
strumentcan recover the correct value for that parameter. Press any
keyand the display reads “Check Settings”. Press any key again to
resumenormal operation. Also, check other settings in the thermome-
ter(if used), such as, filter, units, and resolution. The number follow-
ingthe message is used by authorized technicians.
MemoryInvalid!
Acritical parameter (CAL1, CAL2, Passcode, Meter Due Date, Meter
CalDate, or Serial Number) is corrupt and the instrument cannot re-
coverthe correct value for that parameter. Press any key and the dis-
playreads “Contact Factory”. Contact a Hart Authorized Service
Center(see Section 1.3) for assistance in guiding you through the
processof reentering these parameters.
Note:The parameters stored in the INFO-CON, Probe Wires, Probe
Type,
ProbeParameters, are not checked by the meter during memory
testing.
11.2 Downloading Autologged Data
The 1522 HandheldThermometer readout stores up to 10,000 readings in its
autolog memory.These readings can be downloaded to a computer using the
RS-232 serialport. By default, the 1522 serial port operates at 2400 baud.
However,when downloading autologged readings over the serial port or print-
ing to aserial printer, the instrument temporarily changes its baud rate to 9600
baud to reducethe download time.
The followingsteps should be followed to download autologged data using the
serialport:
1. Connect the instrument to a COM port on the computer using the serial
cable.
2. Run a terminal program such as Windows® Terminal or
HyperTerminal®.
1522 Handheld Thermometer Readout
User’s Guide
58