The sensor is virtually isolated from ambient conditions, allowing the thermocouple to read the true pipe temperature for as long as it is attached * The sensor"s large surface area and increased clamping force help the sensor reach the correct temperature within 30 seconds * Because the jaw is designed for HVAC/R, its clamping ability lets you measure temperatures of pipes that are fixed * at any angle, to walls or other surfaces ATC1 jaw range: 3/8-Inch to 1-3/8-Inch pipe diameter