Keithley 2700, User Manual, Page: 183 / 500

5-10 Rel, Math, Ratio, Channel Average, dB Model 2700 Multimeter/Switch System User’s Manual
mX+b rel
The mX+b function can be used to manually establish a rel value. To do this, set the scale
factor (m) to 1 and set the offset (b) to the rel value. Each subsequent reading will be the
difference between the actual input and the rel value (offset).
Percent
This math function determines percent deviation from a specified reference value. The
percent calculation is performed as follows:
where: Input is the normal display reading.
Reference is the user entered constant.
Percent is the displayed result.
NOTE When using Rel, the rel’ed reading of the input signal is used by the percent
calculation.
Percent configuration
1. Press SHIFT and then MATH to display the math menu.
2. Press the RANGE
Δ
or
∇
key to display “PERCENT,” and press ENTER to
display the present reference value:
REF +1.000000
Δ
(factory default)
3. Key in the reference value. The and keys control cursor position, and the
Δ
and
∇
keys increment/decrement the digit value. To change range, place the cursor
on the multiplier and use the
Δ
and
∇
keys (m =
×
0.001,
Δ
=
×
1, K =
×
1000, and
M =
×
1,000,000). With the cursor on the polarity sign, the
Δ
and
∇
keys toggle
polarity.
4. Press ENTER. The MATH annunciator will turn on, and the result of the
calculation will be displayed. Note that the calculation will be applied to all
measurement functions.
5. To disable mX+b, again press SHIFT and then MATH. The MATH annunciator
will turn off.
NOTE The result of the percent calculation is positive when the input exceeds the
reference and negative when the input is less than the reference.
The result of the percent calculation may be displayed in exponential notation.
For example, a displayed reading of +2.500E+03% is equivalent to 2500%
(2.5K%).
Percent
Input Reference –
Reference
-------------------------------------------
100 %
×
=