Ratio - Keithley 2182 User Manual

5-2 Ratio and Delta
NOTE
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Ratio

Ratio (V1/V2) displays the proportional relationship between the two voltage input channels
(DCV1 and DCV2). Ratio is calculated as follows:
Ratio = V1/V2
Where: V1 is the voltage reading for Channel 1 (DCV1)
Basic procedure
Ratio is selected by pressing the V1/V2 key. The "CH1 / CH2" message appears briefly before
displaying the result of the calculation. The "RA" message is displayed while in Ratio. Ratio is
disabled by selecting a single measurement function (DCV1, DCV2, TEMP1 or TEMP2) or by
selecting Delta.
NOTES
When using the Model 2182/2182A with the Model 6220 or 6221 Current Source,
enhanced Delta and Differential Conductance measurements can be performed.
When using the Model 2182A with the Model 6220 Current Source, Pulsed Delta
measurements can be performed.
See Section I for details on enhanced Delta, Pulsed Delta, and Differential Con-
ductance.
Ratio — Covers the Ratio calculation, and the effects of Filter, Rel and Ranging.
Delta — Explains how to perform Delta measurements, which are used to cancel the
effects of thermal EMFs in the test leads. Features the use of a Keithley SourceMeter
with the Model 2182 to perform Delta measurements. Includes the effects of Filter on
Delta measurements.
SCPI programming — Covers the SCPI commands used to control Ratio and Delta,
and includes programming examples.
Applications — Provides applications that use Ratio and Delta.
V2 is the voltage reading for Channel 2 (DCV2)
• When Ratio is selected, one of the channel annunciators (CH1 or CH2) will
turn on briefly. This indicates the channel that can be controlled by the manual
range key. After that both the CH1 and CH2 annunciators will turn on. See
"Ranging considerations" for details.
• If an overflow condition (OVRFLW) occurs, the range that overflowed will
format the display.
• Ratio readings can be stored in the buffer. See
the buffer.
• Reading HOLD cannot be used with Ratio. Selecting Ratio (or Delta) disables
HOLD.
• LSYNC (line cycle integration) must be enabled when RATIO is selected.
LSYNC turns on automatically when RATIO is selected and turns off
automatically when exiting RATIO.
Section 6 for details on using