How to select a temperature gauge and thermowell

By the Pioneer engineering team, Pirangut, Pune. Updated 31 October 2026.

Pick a range that puts normal temperature in the middle third of the dial, a 100 or 150 mm dial, every-angle mounting if the final orientation is uncertain, a stem long enough to reach the flow, and always a thermowell: barstock SS 316 for steam, process and high-velocity lines, fabricated SS for HVAC and utility water.

Range

Middle third of the scale for normal temperature, maximum still on the dial. Chilled water 0 to 50 °C, hot water 0 to 120 or 0 to 150 °C, steam and thermic fluid 0 to 300 or 0 to 400 °C. Try the temperature range selector.

Mounting

Bottom entry for the top of horizontal pipes, back entry for tank walls and vertical pipes, every-angle when the dial must be turned towards the operator after installation.

Stem and immersion

The temperature-sensitive part of a bimetallic stem is near the tip, so the tip must sit in the flowing fluid, not in the dead zone at the pipe wall. Pioneer stems are 8 mm SS 316 with immersion up to 300 mm; give us the pipe size and we match it.

Thermowell

A thermowell lets the gauge come out without draining the line and protects the stem from pressure and corrosion. Match the bore to the 8 mm stem to keep response quick. Barstock (drilled from solid SS 316) for high pressure, high velocity and steam; fabricated for chilled and hot water. See thermowells.

Dial or digital

Bimetallic at ±1% FSD (EN 13190) for permanent local indication. Digital Pt100 at 0.25% FSD where the difference between two readings matters, such as chiller delta-T or an energy audit.

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