Keithley 2701, Service Manual

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1-30 Performance Verification Model 2701 Service Manual
RTD temperature
1. Connect the precision decade resistance box (listed in Table 1-1 ) to the Model 7700
CH1 and CH11 H and L terminals using four-wire connections. (See Figure 1-12 for
similar connecting scheme.)
2. Install the Model 7700 in Slot 1 of the Model 2701, then turn on the power and allow
the unit to warm up for two hours before proceeding. Be sure the front panel INPUTS
switch is set to the REAR position.
3. Select the temperature function by pressing the TEMP key. Close Channel 1 by press-
ing the CLOSE key and keying in 101.
4. 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.
5. Set the decade resistance box to each of the values shown in Table 1-15 and verify that
the temperature readings are within the required limits. Open Channel 1when finished.
Table 1-15
Plug-in module 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.