power meter is using an AD8362 logarithmic power sensor chip. There is
a 20dB attenuator between the input connector and the sensor chip.So
the maximum power at the input BNC can be 20 dBm.
Additional attenuator is needed to measure higher power.
dynamic range of the power meter is 50 dB. Noise floor is -55dBm.
Linearity and offset is calibrated at 10,50,150,450,1000,1500 and 2000
The instrument is powered by a 9 V battery cell.