A walking body-voltage test under ANSI/ESD STM97.2-2016 requires a hand-held electrode, voltage measurement apparatus, a recording device and humidity instrumentation (section 5.1).
Hand-held electrode
Section 5.1.1 describes the hand-held electrode as a stainless steel, brass, or copper round or tubular stock, approximately 2.5 cm (1 inch) in diameter and 7.5 cm (3 inches) or greater in length. A banana plug receptacle or screw connector is attached to one end of the cylinder.
Voltage measurement apparatus
Section 5.1.3 specifies a charged plate monitor or equivalent with:
- an input resistance greater than 1.0 × 10¹⁴ ohms
- a capacitance of 20 pF or less
- the capability to measure voltages from 10 volts up to a minimum of 1,000 volts with an accuracy of ±10%
The monitor must have an analog or digital output to connect to a recording device.
Recording device
Under section 5.1.4, the recording device may be a chart recorder, scope, or data logger, such as an analog-to-digital converter connected to a personal computer. The system time constant must be not more than 0.2 second.
Humidity instrumentation
Under section 5.1.2, the humidity instrumentation must be accurate to ±3% RH in the operational range.
Frequently Asked Questions
STM97.2-2016 permits a charged plate monitor or equivalent with input resistance greater than 1.0 × 10¹⁴ ohms, capacitance no greater than 20 pF, and a measuring range from 10 volts to at least 1,000 volts with ±10% accuracy. The monitor must have an analog or digital output for connection to a recording device.
STM97.2-2016 lists a data logger, such as an analog-to-digital converter connected to a personal computer, among the recording-device options. The recording system’s time constant must be no more than 0.2 second.
STM97.2-2016 requires humidity instrumentation accurate to ±3% RH within its operational range.