MU/04
Combine wideband true rms converter with panel meter, for accurate analogue indication of rms/pk. sine level of periodic signals.
Crest factor (CF) up to 4, equivalent to 16 : 1mark/space ratio rectangular wave, causes little impairment to rms accuracy. Peak sine reading accuracy is dependant on waveform purity, being √2 scaled from the rms converter output.
Both have fixed, 1Vpk. sine/rms full scale sensitivity and dual 0/1, 0/3.16 fsd meter scaling, and are intended as level monitors for CA/04 O/P2, DM, VM/04 etc... the CA etc... range switch determines meter scale and scale multiplier and should be used to contain the meter display within the range 30/100% fsd (10dB) for adequate resolution and accuracy.

MU/04/L
This includes a 60dB dynamic range logarithmic converter, finding application where the limited, 10dB range of linear displays imposes constraints, i.e., in wideband frequency response measurement.
In absolute terms physical measurement boundaries are determinated by linear range and noise floor, and generally far exceed the resolution limited range of linear visual displays (meters etc.) which may need auto/manual scaling adjustment to track a variable.

MINIMUM OPERATING FREQUENCY
The rms converter generates a 1/f frequency dependant ripple component as a function of the averaging process. This in turn introduces a 1/f dependant error component, thus defining minimum frequency in terms of averaging time.

GENERAL
These products generate a log/lin output proportional to the rms value of periodic signals, for use with level recorders, and provide analogue meter display. The display has interpretative advantages re digital readouts where the signal is modulated, where perhaps two or more digits of the latter may be subject to uncertainty and render min/max readings difficult.