Filter, Rel, And Ranging Considerations - Keithley 2182 User Manual

5-4 Ratio and Delta

Filter, Rel, and Ranging considerations

Filter considerations
As explained in
channel. However, the Filter configuration for Channel 1 is applied to both channels when Ratio
is enabled. The Filter state and configuration for Channel 2 are ignored. Channel 1 Filter has
priority because it has the most sensitive measurement range (10mV) and may therefore be
configured to provide more filtering than Channel 2.
When the FILT annunciator is on while in Ratio, the Channel 1 (DCV1) Filter settings are
applied to both input channels. When the FILT annunciator is off, filtering is not used.
When using Filter, Ratio is calculated as follows:
Ratio = Filt V1 / Filt V2
where: Filt V1 is the filtered reading for Channel 1 voltage input.
Keep in mind that the Filter settings are applied to the input channels, not on the result of
Ratio.
The FILT key is operational while in Ratio. Pressing FILT will either disable Filter for both
channels or enable Filter for both channels (FILT annunciator turns on). However, remember
that even though Filter can be enabled for both channels, only the Channel 1 Filter settings are
used.
NOTE
Rel (Relative) considerations
As explained in
When Ratio is enabled, any established Rel values are applied to the respective channels before
the calculation is performed.
Ratio is calculated as follows:
Ratio = (Filt V1 - V1 Rel) / (Filt V2 - V2 Rel)
where: Filt V1 is the filtered reading for Channel 1 voltage input.
Section 3, a unique Filter configuration can be established for each voltage
Filt V2 is the filtered reading for Channel 2 voltage input.
The filter configuration menu cannot be accessed while in Ratio. To make filter
configuration changes, you must first disable Ratio. This can be done by returning to
Channel 1 (press DCV1).
Section 3, a separate Rel value can be established for each voltage channel.
V1 Rel is the Rel value established for Channel 1.
Filt V2 is the filtered reading for Channel 2 voltage input.
V2 Rel is the Rel value established for Channel 2.