entered, not measured. Normally, the fixed points that are used will be the stan-
dard specified fixed points for the ITS-90 such as the triple point of water, the
freezing point of tin, etc.
The setup options for the fixed-point calibration are shown in Table 5. Options
not indicated are irrelevant. The calibration may done for just one probe, for
multiple probes using just one channel, or multiple probes using multiple
channels.
7.4.4.2.2
Comparison Calibration With Manual Sequencing
With this method of calibration, the probes are calibrated in baths or other sta-
ble temperature sources and the temperatures are measured with a reference
SPRT. Fixed points may be used for one or more of the calibration points. User
input will be required to initiate the resistance measurement at each point. The
calibration may be done either for just one probe, for multiple probes using just
one channel, or multiple probes using multiple channels.
The setup parameters for the comparison calibration method are shown in Table
7. Options not indicated are irrelevant. In the table, PROBE 2 is shown set up
as the reference SPRT on INPUT 2 as an example. A different probe and chan-
nel may be used instead. For best accuracy, the temperature measurement
should be repeated between each probe’s resistance measurement (TEMP set to
REPEAT).
7.4.4.2.3
Comparison Calibration With Automatic Sequencing
With this method of calibration, the probes are calibrated in a bath or other sta-
ble temperature source and the temperatures are measured with a reference
SPRT. Fixed points may be used for one or more calibration points. All the
measurements at each calibration point are made automatically with a specified
amount of delay between each. This method is useful when using the
1575/1590 in conjunction with the 2590 Scanner for calibrating a large number
of probes simultaneously.
1575/1590 Thermometer Readout
User’s Guide
56
REFR: FIXED POINTS
TEMP: ONCE
MEAS: PROMPT
Table 6
Fixed-point Calibration Setup
REFR: PROBE 2
CHANNEL: INPUT 2
TEMP: REPEAT
MEAS: PROMPT
RREF: NORM
Table 7
Manual Comparison
Setup
