HP 34970A User Manual page 109

Chapter 4 Features and Functions
Temperature Measurement Configuration
RTD Measurements
To connect an RTD to the module's screw terminals, see page 21.
The instrument supports RTD s with
or = 0.00391 using ITS -90 software conversions. The default is
= 0.00385.
The resistance of an RTD is nominal at 0 C and is referred to as R
The instrument can measure RTD s with R
The default is R = 100 .
0
"PT100" is a special label that is sometimes used to refer to an
RTD with = 0.00385 and R
You can measure RTD s using a 2-wire or 4-wire measurement
method. The 4-wire method provides the most accurate way to
measure small resistances. Connection lead resistance is
automatically removed using the 4-wire method.
For 4-wire RTD measurements, the instrument automatically pairs
channel n with channel n+10 (34901A) or n+8 (34902A) to provide
the source and sense connections. For example, make the source
connections to the HI and LO terminals on channel 2 and the sense
connections to the HI and LO terminals on channel 12.
Front-Panel Operation: To select the 2-wire or 4-wire RTD function
for the active channel, choose the following items.
TEMPERATURE , RTD , RTD 4W
To select the nominal resistance (R
the following item.
Ro:100.000,0 OHM
To select the RTD type ( = 0.00385 or 0.00391) for the active
channel, choose the following item.
ALPHA 0.00385
110
= 0.00385 (DIN / IEC 751)
values from 49 to 2.1 k .
0
= 100 .
0
) for the active channel, choose
0
.
0