Keithley 2701, Service Manual

Page: 31 / 168

Model 2701 Service Manual Performance Verification 1-17
RTD temperature
1. Connect the precision decade resistance box (listed in Table 1-1 ) to the Model 2701
INPUT and SENSE jacks using four-wire connections. (See Figure 1-5 for similar
connecting scheme.) Be sure the INPUTS switch is in the FRONT position.
2. Configure the Model 2701 temperature function for °C units and RTD temperature
sensor (
α
=0.00385) as follows:
a. Press SHIFT then SENSOR and note the unit displays the temperature units:
UNITS: C.
b. Press ENTER and note the unit displays the sensor type: SENS: TCOUPLE.
c. Using the cursor and range keys, set the display as follows: SENS: 4W-RTD.
d. Press ENTER and note the unit displays: TYPE: PT100.
e. Using the cursor and range keys, set the unit for the following display: TYPE:
PT385.
f. Press ENTER to complete the temperature configuration process.
3. Select the temperature function by pressing the TEMP key.
4. Set the decade resistance box to each of the values shown in Table 1-8 and verify that
the temperature readings are within the required limits.
Table 1-8
Four-wire RTD temperature verification reading limits
Applied resistance* Reading limits (1 year, 18°C to 28°C)
22.80
Ω
100.00
Ω
313.59
Ω
-190.06 to -189.94°C
-0.06 to +0.06°C
599.94 to 600.06°C
*Based on
α
= 0.00385. See text.