Temperature recordings are made by lowering the thermometer down a tube with a rope or chain. Tubes and chains are manufactured to suit the depth required. The thermometer bulb is encased in wax to allow a slow change of temperature to be recorded and when the instrument is recovered, it retains the reading. The tube is supplied with a solid brass sealing cap.

Measuring range from -10°C to 45°C x 0.5°. Other ranges available to order.

Tube nominal immersions, measured from flange to bulb of thermometer: 300mm, 500mm and 1000mm