Problem Solution
Incorrectresistance or voltage
reading
Whileattempting to measure resistance or voltage, the display shows an incorrect value or no value at
all
(..........).
Considerth e following possibilities:
Pooror incorrect connection of the probe. A common mistake is to connect the wires of the probe
tothe wrong terminals. Check the wiring carefully, especially when using a four-wire PRT (see Section
6.4.1).Make sure the lead wires are fastened down tightly.
Open,shorted, or damaged sensor or lead wires. In the case of resistance sensors check the resis-
tanceacross the sensor using a hand-held DMM. Also check the resistance between common pairs of
leads.Check to make sure there is no conductivity between any of the leads and the probe sheath.
Usea good-quality sensor to avoid errors caused by drift, hysteresis, or insulation leakage. In the case
ofthermocouples, use a hand-held DMM to check its voltage.
Impropersetting for three or four-wire probe. Make sure the correct wiring type is selected Select-
ingthree-wire input while using four-wire probes may cause errors of 0.01 to 0.1 ohms. Selecting
four-wireinput while using three-wire probes will result in erratic or out-of-range readings (see Section
7.2.1.1).
Electricalinterference. Intense radio-frequency radiation near the 1529 or probes can induce noise
intothe measurement circuits resulting in erratic readings. The 1529 is intended to operate in a labora-
toryenvironment with limited radio-frequency noise. If interference seems to be a problem you might
tryeliminating the source of interference or moving the 1529 to a different location. A well-grounded,
shieldedcable should be used for the probe leads.
Stemconduction error. The problem may be that the actual temperature of the sensor is not what
youexpect. This is often the result of stem conduction where heat flowing through the stem of the
probeto ambient affects the temperature of the probe. It is very important that probes be inserted to an
adequatedepth into the material being measured. Measuring temperature using a surface sensor can
beespecially difficult as the sensor is directly exposed to ambient.
Wrongcalibration parameters. The problem may be that the calibration parameters for the 1529 are
invalid.Check the parameters currently stored in the unit against those listed on the 1529 Report of
Calibration.
Blankscreen Thescreen lights up when the 1529 is switched on but the screen appears blank. This problem
canbe caused by improper adjustment of the contrast. After the power is switched on allow the 1529
atleast one minute to complete its self-test and power on sequence. Then, try to adjust the contrast
usingthe contrast buttons.
Errormessage at power up The1529 reports an error during the power up self-test. On power up the 1529 performs a series of
self-teststo check the operation of all its components and each of the modules. The results of the
self-testsare reported on the screen. Normally, all tests report ‘OK’. Below is a table of error messages
andrecommended actions to correct the error. Often these errors can be corrected by completing the
actionslisted. A failure of one or more component causes error messages to be reported. Component
failuresgenerally require a qualified factory technician to replace the faulty component. Contact an Au-
thorizedService Center (see Section 1.3).
Temperaturenot
updating
The1529 measure period may be set to a long interval. Check the measure period.
11.1.1 Self-Test Error Messages

The followingmessages may appear during the self-test. If the recommended

action failsto correct the error, contact an Authorized Service Center (see Sec-

tion 1.3) for assistance.

Message RecommendedAction
SYSTEMS:INVALID TIME Setthe date and time.
SYSTEMS:SERIAL PORT FAILURE Cyclethe power.
1529 Chub-E4 Thermometer Readout
User’s Guide
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