For the switching strategy described in the last post to work we need to know

• Csl, the parasitic capacitance of the short loop
• Cll, the parasitic capacitance of the long loop
• The value of each of the capacitors

Measuring Csl

Csl is visible at the connectors if the capacitance is set to zero. (SCPI command: SOURce:CAPacitance 0) This will open the bypass relay and all relays of decade 1.

Command ADJustment:SLOop:CAPacitance <cmeas> sets Csl.

Measuring Cll

Csl can be measured if all decade relays are open but the bypass relay is closed. (SCPI command: ADJustment:LLOP:OPEN:STATe ON).

Command ADJustment:LLOop:CAPacitance <cmeas> sets Cll.

Measuring Capacitors

To measure the capacitance of a specific capacitor we can explicitly close one relay using command SOURce:DECade<dec>:RELay <byp>, <rel>.

Where <dec> is the decade [1..7], <byp> is the state of the bypass, ON for active, OFF for inactive and <rel> is the relay number [0..5] with 0 signifying all relays off.

To set the measured value use command ADJustment:DECade<dec>:RELay<rel>:CAPacitance <cmeas>

with <dec> in range [1..7] and <rel> in range [1..5].