Deviation; Ratio; Logarithmic - Keithley 6517B Reference Manual

Model 6517B Electrometer Reference Manual

Deviation

The following math calculation provides the deviation between the normal display reading and the
user specified reference value:
Where:

X is the normal display reading

Y is the specified reference value
Deviation is enabled through the CONFIGURE MATH menu.

Ratio

The following calculation divides the normal display reading by the user specified reference value:
Where:

X is the normal display reading

Y is the specified reference value
Ratio is enabled through the CONFIGURE MATH menu.

Logarithmic

This calculation converts input readings to logarithmic base 10 values. The calculation is shown as
follows:
Where:

X is the input reading

Y is the logarithmic result
Example: Assume that exactly 1mA is being measured by the Model 6517B.
Note that this calculation uses the absolute value of the normal input reading since you cannot
compute the log of a negative number.
6517B-901-01 Rev. C / August 2015
log X = Y
10
log 1.000000mA = -3
10
Section 9: Filters and math
9-9