Keithley 6430, Instruction Manual

Page: 162 / 558

7-6 Relative and Math
Percent deviation
This calculation provides the percent deviation between the normal display reading and the
user set reference value:
where: X is the normal display measurement reading (V, I, or
Ω
).
Y is the reference value.
When prompted to enter the reference value (Y), you can enter the value or have the
SourceMeter acquire the reference value. To acquire the reference value, turn on the output and
press AUTO. The SourceMeter will perform a measurement and display that reading as the ref-
erence.
Limit Testing — After the reference value is entered, you will be prompted to enter high and
low tolerances (in %) for the reference value. These tolerances set the high and low limits for
Limit 2 test.
For example, perform the following steps to test 1k
Ω
, 1% resistors:
1. Select the
Ω
function, select the 1k
Ω
measurement range (or use AUTO range), and
connect the resistor to be tested to the SourceMeter.
2. Configure the percent deviation math function:
a. Press CONFIG, press FCTN, then select %DEV.
b. Set the reference (REF) value to +1.000000 k, then press ENTER.
c. Set the high tolerance (HI TOL) to 01.00%, then press ENTER.
d. Set the low tolerance (LO TOL) to 01.00%, then press ENTER.
3. Turn the output on. The measured reading of the resistor is displayed.
4. Press FCTN to select the percent deviation math function. The actual tolerance of the
resistor will be displayed along with the result of the limit test. If the resistor reading is
within ±1% of 1k
Ω
, the “PASS” test message is displayed. If outside the 1% tolerance,
the “FAIL” message is displayed.
5. When finished, turn the ouput off.
NOTE
The reading format is fixed at ±XXX.XXX%
NOTE Limit testing can be disabled by pressing the LIMIT key.
%Deviation
X Y –
( )
Y
-------------------
100 ×
=