Temperature - Keithley 2001 Operator's Manual

When AC+DC coupling is selected, the blocking capacitor is
removed. Subsequent frequency measurements will reflect
both the AC and DC components of the signal.
You can set the frequency coupling as follows:
1. From the CONFIGURE FREQUENCY menu, select
COUPLING and press ENTER. The following menu is
displayed:
SET FREQ COUPLING
AC AC+DC
2. Highlight the desired coupling and press ENTER.
Multiple displays
There are two multiple displays just for the frequency
function:
• Period calculation
• Trigger level
The multiple display showing the period of the waveform is
calculated from the frequency measurement and, as such, is
only available when the frequency does not equal 0Hz. It is
also unavailable when math is enabled.
The trigger level multiple display is the same message that is
displayed when the trigger level is changed, but it is a perma-
nent display.
3.4.5

Temperature

The Model 2001 measures temperature with two different
sensor types: RTDs and thermocouples. With RTDs, the
Model 2001 can measure temperature between -200°C and
+630°C. RTDs can be connected to the input terminals or the
optional Model 2001-SCAN scanner card.
With thermocouples connected to an external thermocouple
card, such as a Model 7057A or 7402 in a Model 7001
Switch System, the instrument measures temperature over a
range that is dependent on the thermocouple type. (Refer to
the Specifications.
Temperature measurements
Assuming "bench reset" conditions (see
the basic procedure to measure temperature with a type
PT385 4-wire RTD (the default sensor) is as follows:
1. Connect the RTD sensor to the Model 2001 as shown in
Figure 3-17. You can use banana plugs (with the front or
rear inputs), or the optional Model 8680 RTD Probe
2001-900-01 Rev. K/ August 2010
The procedure for measuring temperature with 3-wire and 2-
wire RTDs is similar. (See
connection diagrams.) Be sure that the temperature function
is configured for the correct sensor type. (Use the 4-WIRE-
RTD selection for a 3-wire RTD sensor.)
To measure temperature with thermocouples, you need to
connect the thermocouples to a suitable external scanner
card, such as the Keithley Model 7057A or 7402. These
cards must be inserted into a Model 705 or 706 Scanner or
the Model 7001 Switch System, as shown in
The thermocouple cards use Channel 1 as the reference
junction, and must be configured on the Model 2001 for
voltage reference and offset.
paragraph 3.12.1),
Adapter (with the front inputs). Place the INPUTS but-
ton in the appropriate position. RTDs can also be con-
nected to the optional Model 2001-SCAN scanner card.
(See the Model 2001-SCAN manual.)
2. Select the TEMP function.
CAUTION
Do not exceed 1100V peak between IN-
PUT HI and LO, or 350V peak between
SENSE 4 WIRE HI and LO, or instru-
ment damage may occur.
3. Observe the display. If the "Overflow" message is
shown, the RTD might not be connected properly.
4. Take a reading from the display.
Front Panel Operation
Figure 3-18 and Figure 3-19
Figure
for
3-20.
3-43