Thermometer Readout User's Guide

6.8.2 Enabling the Channel
Channels are set first by selecting either simultaneous or scan mode in the
CHANNEL menu CHANNEL MODE function. Simultaneous mode shows one
to four channels in the upper display simultaneously. Scan mode shows one
channel at a time (in large digit format) scanning through one to four channels
depending on the channels that are enabled. After the mode has been selected,
use the CHANNEL menu ENABLE CHANNEL function, to select the channel
to be displayed. Any channel set to ‘Off’ is not displayed. See Sections 7.1.3,
Channel Mode, and 7.1.2, Enable Channel, for more information.
6.8.3 Selecting Conversion Type and Probe Characterization
Before the 1529 can accurately measure temperature, it must be configured to
calculate temperature from the resistance or voltage of the sensor. There are
many temperature conversion algorithms available and the one to use depends
on the type of sensor and its calibration. Many conversion algorithms use coef
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ficients that characterize the sensor. Coefficients are determined when the sen
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sor is calibrated. SPRTs and RTDs often use the ITS-90 algorithms and are
provided with ITS-90 characterization coefficients. Thermistors often use the
Steinhart-Hart algorithms and coefficients. Thermocouples use standard tables
or equations depending on its type. For additional information on conversion
types, see Section 7.2, Probe Menu.
The conversion type and characterization coefficients for a sensor are specified
using the PROBE menu EDIT PROBE function (see Section 7.2.1).
6.9 Fast Measurement Mode
Fast Measurement Mode applies to measure periods of 0.1, 0.2, or 0.5 seconds.
This mode allows measurements to be displayed or logged quickly.
Normally, when each measurement is made a self-calibration of the measure
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ment circuit is performed simultaneously during the measurement process to
offset errors from component drift and spurious EMFs. For measure periods of
0.1, 0.2, and 0.5 seconds, the fast measurement rate is achieved by foregoing
the self-calibration. The drawback to this Fast Measurement Mode is the accu
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racy of the measurement may be poor and subject to drift. Accuracy can be
temporarily improved using the AUTO-CAL function that appears in the
CHANNEL menu when in this Fast Measurement Mode. The AUTO-CAL
function causes the instrument to perform a single self-calibration of the mea
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surement circuit then resume fast measuring (without automatic
self-calibration).
See Section 8.1.1 for detailed information on using the Fast Measurement
Mode.
1529 Chub-E4 Thermometer Readout
User’s Guide
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