Applied Physics Systems offers two models of milliammeters, the bench top model 428D and the portable battery operated model 428P. Both models are intended for use in applications where small current measurements are required without breaking the circuit. The probe for each model can be clipped onto wires up to 0.160 in. in diameter and currents as small as 20 microamps can be measured.

The model 428D can measure and display small currents up to 10 amps in a variety of applications including high voltage, power supply current and ripple and small AD or DC current changes superimposed on a DC current.

The model 428P is battery operated, water resistant and designed to operate in field conditions. The model 428P can measure currents up to 2 amps in either DC or AC mode. The measured current is displayed on a 3 1/2 digit LCD; a backlight on the display aids in nighttime viewing. Magnetic fields can also be measured using either the model 428D or the model 428P by using optional magnetometer probes.