Fluke Biomedical DALE601 - Manual (Page 39)

Operation
Measuring Patient Auxiliary Current
2
2-15
Measuring Patient Auxiliary Current
Patient Auxiliary Current (I
A
) (lead-to-lead current) flows from any patient
lead to any other patient lead and to all other leads connected together,
including:
• Bias current of the input amplifier
• Reverse leakage current of input protection diodes
• Lead-off sensing current
• Impedance measurement current such as for respiration
The currents can be dc or ac or a combination of both. They are measured
using a true rms to provide the common base necessary for accurate readout
with a variety of common waveforms.
Measurement is made with a completely floating circuit to avoid extraneous
leakage currents to ground introducing errors. Measurement is made from the
selected lead to all other leads connected together, thus reducing the
permutations required to cover all possibilities.
To measure patient auxiliary current:
1. Connect the patient leads to the universal connectors on the front of the
analyzer.
2. Set the FUNCTION switch to PATIENT AUX CURRENT .
MAI N S V OLTAGE
CURRE N T AMPS
EARTH RESISTA N CE
EARTH LEAKAGE
E N CLOSURE LEAKAGE
PATIE N T LEAD LEAKAGE
PATIE N T AUX CURRE N T
M.A.P.
EXTER N AL
fcu09.eps