Two switch-selectable measurement ranges (2 kV/cm and 20 kV/cm)

Recorder output to pass measurements to auxiliary instruments to display or record the data

Intrinsically safe sensors are approved for use in hazardous locations when used with approved IS barriers

Remote sensors can be located up to 1000 feet from the monitor

Chopper-stabilized measurement technique is drift free, even in ionized environments

An AC adaptor is provided to recharge the batteries and to operate the Model 257D during longer-term tests