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NMRR (Normal Mode Rejection Ratio)
NMRR is the DMM's ability to reject unwanted AC noise effect,
which causes inaccurate DC measurements. NMRR is typically
specified in terms of dB (decibel). This series has a NMRR
specification of >60dB at 50 and 60Hz, which means a good
ability to reject the effect of AC noise in DC measurements.
CMRR (Common Mode Rejection Ratio)
Common mode voltage is voltage present on both the COM
and VOLTAGE input terminals of a DMM, with respect to
ground. CMRR is the DMM's ability to reject common mode
voltage effect, which causes digit rattle or offset in voltage
measurements. This series has a CMRR specifications of
>60dB at DC to 60Hz in ACV function; and >120dB at DC, 50
and 60Hz in DCV function.
