Step and Touch Instrument

Video Overview

Step and Touch Video


The SNT Kit contains everything you need to monitor step and touch potential, including:

Step and Touch Instrument Kit

User Guide

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Read the User Guide

The Step and Touch (SNT) instrument monitors and alarms "Step and Touch" potential caused by ground potential rise. When used properly, the SNT can enhance the safety of transmission line crews.

Alarm Ranges

The SNT provides audible and visual alarm warnings if the probe voltage is in a dangerous range. Each voltage range has a distinct pattern of bright flashing LEDs and audible 80 dB(A) alert. (The SNT also detects and warns of Lost Probe Connection and Low Battery).

Range Instrument Actions
0 - 100V SNT Step and Touch Instrument with Green LEDs lit
101 - 499V SNT Step and Touch Instrument with Yellow LEDs litQuiet Alarm
500V+ SNT Step and Touch Instrument with Yellow LEDs litLoud Alarm

Utility Tested & Field Proven

An innovation by Bonneville Power Administration engineers, the SNT Instrument has been helping ensure the safety of BPA line crews since 2003.

Starting in 2011, the SNT is available to other customers from the long-time manufacturer of the SNT instrument, Delta Computer Systems, Inc.


Full Scale Voltage 50 Hz to 60 Hz999 Vrms sine wave with < 5% Total Harmonic Distortion
Absolute Max Probe Voltage5000 Vrms
Step Voltage Response95% rise time < 1 second.
During probe check, step response may be up to 4.5 seconds.
Accuracy1% typical for 500 V (3.5% from -30°C to +50°C)
Probe Impedance20 MΩ
Voltages Displayed10 to 999 Vrms
Standard Alarm Voltage Ranges (others can be programmed by the factory as an option)0 to 100 — Green LEDs slow flash
101 to 499 — Yellow LEDs flash, beeps every second
500 plus — Red LEDs flash rapidly, beeps rapidly
Audio Alert90 dB at 2 feet
DisplaysVoltage Display
3 digit voltage using bright seven segment displays
Threshold Warning
Three high intensity Green LEDs
Five high intensity Yellow LEDs
Eight high intensity Red LEDs
Check Probe & Battery Low
Blue LEDs
Probe Connection CheckPerformed every 60 seconds. Duration is 3.5 seconds, during which time the probe voltage is not sampled.
Battery Life60 hours typical.
Low battery is indicated by LED, very low battery activates fault mode (flashing LEDs and audible alert).
Battery TypeNi-MH, 500 charge cycles typical
Ingress ProtectionDesigned for IP64
Instrument Weight907 grams (2 pounds)
Kit Weight10K grams (22 pounds) includes instrument and case
Case Size (H × W × L)19.1 cm × 39.6 cm × 50.2 cm (7.5 in × 15.6 in × 19.75 in)

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