Monroe 257D is a high-precision，portable electrostatic fieldmeter
Features：
Battery or line operation-AC power module included
Two ranges:±2kV/cm and ±20kV/cm
Remote probe for easy monitoring of hard-to-reach locations up to 1000 feet
Chopper stabilizer for accurate measurements in ionized environments
Recorder output for unattended monitoring
Unequaled accuracy,stability and versatility
Ranges:±2kV/cm and ±20kV/cm
Sensitivity：1V/m and 10V/m，respectively
Static accuracy：Better than 5% of reading
Drift：＜30V/m/hour,non-cumulative after 30-minutes stablization,referred to input
Noise: ＜10V/m rms.0-200Hz referred to input
Response speed: 250ms 10% to 90%(typical)
Analog output:±10kV/m = ±1.0V output（＜ 10 ohm impedance）
Batteries:Built-in,rechargeable,gel-type,12V,1.2AH,＞8 hours with backlight on-charging system on-board,＜6 hours recharging time.
AC power adapter:Power adapter supplied:input:100-240VAC/47 to 63 Hz/260mA
Weight: 2lbs.,6oz(1.1kg)w/batteries
Operating environment:25℃，±10℃，0-85% RH non-condensing,unaffected by ionized environment
