Calibration - Isolated current meter - Measuring patient auxiliary leakage current

[sunny.day]

Hello,
According to IEC 60601 a tester for medical equipment must have isolated curret meter for measure patient auxiliary leakage current.
How to calibrate this A-meter? Direct with current calibrator, one pol is grounded. Is this ok?
Is it necessary check CMRR? If yes, what is max voltage, frequency?
Can anyone help me?

 

[Marc]

Is it necessary check CMMR

For those of us following along:

CMMR = ????

 

[sunny.day]

Mistake,
right is CMRR - common mode rejection ratio.

 

[Benjamin Weber]

Hello,
According to IEC 60601 a tester for medical equipment must have isolated curret meter for measure patient auxiliary leakage current.
How to calibrate this A-meter? Direct with current calibrator, one pol is grounded. Is this ok?
Is it necessary check CMRR? If yes, what is max voltage, frequency?
Can anyone help me?

Don't get 60601-1 wrong here. The patient auxiliary current is not measured directly with an ampere-meter.

Leakage and patient auxiliary current measurements are described in cl. 8.7.3 of IEC 60601-1. The measuring device (MD) consists of a first low-pass-filter and a shunt resistor mimicing the patient's impedance. The current is measured by the voltage drop across this 1kOhm shunt resistor with a voltage-meter.

This volt-meter shall be isolated and be capable of true effective measurements of DC and AC components.

 

[Benjamin Weber]

The specifications of the measuring device (MD) and of the volt-meter are explained in detail in cl. 8.7.4.4 of IEC 60601-1.