HP E1313A Manual page 78

Note
Thermocouple
Reference Temperature
Setting-up a Reference
Temperature Measurement
Chapter 3
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A scan list must include a reference temperature channel before related
thermocouple channels, or the fixed reference temperature must have been
supplied before starting to scan thermocouple channels (see following section).
The isothermal reference temperature is required for thermocouple
temperature EU conversions. The Reference Temperature Register must be
loaded with the current reference temperature before thermocouple channels
are scanned. The Reference Temperature Register can be loaded two ways:
1. By measuring the temperature of an isothermal reference junction
during a scan.
2. By supplying a constant temperature value (that of a controlled
temperature reference junction) before a scan is started.
The
[SENSe:]REFerence <
command links channels to the reference temperature EU conversion.
When the channel is scanned, the reference temperature is measured and
stored in the Reference Temperature Register, the FIFO, and the CVT. The
reference value is applied to all subsequent thermocouple channel
measurements until another reference temperature value is stored in the
Reference Temperature Register.
•
The < ch_list > parameter specifies any sense channel that is
connected to the reference temperature sensor.
•
The < sensor_type >
. This is a resistance temperature measurement and uses the
CUSTom
on-board 122 µA current source for all types.
•
The < sub_type > parameter must specify:
For RTDs; 85 or 92
–
Ohms/Ohm/Degree C temperature coefficients, respectively).
For Thermistors; only
–
For CUSTom; only 1 (contact your HP Field Engineer for Custom
–
EU algorithms).
•
The optional range
<
range. When not specified or set to
To set channel 12 to measure the isothermal reference temperature on the
HP E1413's terminal module (with built-in 5,000 Ohm thermistor) send
SENS:REF THER,5000,(@112)
sensor_type sub_type
>,< >,[<
parameter can specify THERmistor
(for 100 Ohm RTDs with 0.003
5000 (See previous note on page 75).
parameter can be used to choose a fixed A/D
>
, the module uses autorange.
AUTO
On-board thermistor connected
to channel 12.
Using the HP E1313/E1413
range ch_list
>,](@< >)
, RTD , or
85 or 0.003 92
77