Temperature gauges
Pioneer makes all-stainless bimetallic temperature gauges with 100 to 250 mm dials and ranges from −50 to +50 °C up to 0 to 600 °C, ±1% FSD as per EN 13190, in bottom, back and every-angle mounting, and supplies digital Pt100 gauges and SS thermowells to go with them.
Choosing the range
Put the normal operating temperature in the middle third of the dial.
| Service | Range to order |
|---|---|
| Chilled water, 6–12 °C | 0 to 50 °C |
| Condenser water, 30–37 °C | 0 to 100 °C (or 0 to 50 °C) |
| Hot water, 60–80 °C | 0 to 120 °C or 0 to 150 °C |
| Steam at 7 kg/cm² (about 170 °C) | 0 to 250 °C or 0 to 300 °C |
| Thermic fluid, 250 °C | 0 to 400 °C |
| Cold rooms, −20 °C | −50 to +50 °C |
Always with a thermowell
On any pressurised or flowing line the gauge goes into a thermowell, so it can be removed without draining the system. Order both together and we match the bore to the 8 mm stem and the length to your pipe size.
Digital temperature gauge (Pt100)
Pioneer's digital temperature gauge uses a Pt100 sensor and a 15 mm seven-segment LCD in a 100 mm SS 304 case, reads to 0.25% FSD and runs on four 1.5 V alkaline cells. It suits energy audits, chiller performance checks and any point where a closer reading than a dial gauge is needed.
A 0 to 120 °C dial gauge at ±1% FSD can be 1.2 °C out anywhere on the scale. For chiller delta-T, the difference that tells you whether the machine is doing its job is often only 5 °C, so that error matters. The Pt100 digital gauge is about four times tighter and has no parallax.
| Parameter | Value |
|---|---|
| Sensor | Pt100 |
| Range (data sheet) | 30 to 60 °C; other ranges confirmed at enquiry |
| Case size | 100 mm |
| Display | Seven-segment LCD, 15 mm digit height |
| Accuracy | 0.25% FSD |
| Over-range protection | 130% FSD |
| Case | SS 304 |
| Stem and wetted parts | SS 316, 8 mm diameter, 150 mm long |
| Socket | SS 304 |
| Mounting and connection | Bottom, 1/2" BSP (M) |
| Power | 4 × 1.5 V alkaline cells |
| Thermowell | SS 304, 100 mm long, 1/2" BSP (F × M) |
Thermowells
A thermowell is a closed tube that sits in the pipe or vessel and holds the temperature gauge or sensor, so it can be removed without draining the line. Pioneer supplies barstock thermowells drilled from SS 316 bar for high-pressure and high-velocity service, and fabricated SS thermowells for HVAC and utility lines, matched to the gauge stem and immersion length.
Most temperature-gauge problems on site are really thermowell problems: a bore too large for the stem (slow, wrong readings), a well too short to reach the flow, or a fabricated well on a high-velocity line where a barstock well was needed.
Order the thermowell with the gauge and give us the pipe size, the medium, pressure and velocity. We match the bore to the 8 mm stem and the length to the pipe. On high-velocity steam and gas lines, the well's strength and vibration behaviour should be checked by the designer, commonly to ASME PTC 19.3 TW.
| Parameter | Value |
|---|---|
| Materials | SS 316 (barstock); SS 304 / SS 316 (fabricated) |
| Bore | To suit 8 mm gauge stem (other stems on request) |
| Process connection | 1/2" BSP typical; NPT and flanged on request |
| Instrument connection | 1/2" BSP (F) |
| Length | To suit pipe size and immersion; 100 mm standard for digital gauge |
| Tip | Closed, rounded or tapered |
Data sheet
Questions buyers ask
What is the difference between bottom, back and every-angle mounting?
Bottom entry: stem under the case, for the top of horizontal pipes. Back entry: stem behind the dial, for tank walls. Every-angle: the case swivels and tilts so the dial can face the operator after installation.
How accurate is a bimetallic temperature gauge?
±1% FSD as per EN 13190, so a 0 to 120 °C gauge reads within about ±1.2 °C. The digital Pt100 gauge is 0.25% FSD.
Do you make mercury-in-steel thermometers?
For new projects we recommend bimetallic or digital gauges. Send your specification and we confirm what we can supply.
How accurate is the digital temperature gauge?
0.25% of full scale, roughly four times tighter than a ±1% FSD bimetallic gauge.
Does the digital temperature gauge need wiring?
No. It runs on four 1.5 V alkaline cells.
Is a thermowell included with the digital temperature gauge?
The data sheet lists an SS 304 thermowell, 100 mm long, 1/2" BSP (F × M). Confirm length for your pipe size at enquiry.
Barstock or fabricated thermowell?
Barstock for high pressure, high velocity, steam and process service. Fabricated for HVAC and utility water lines where pressure and velocity are moderate.
Does a thermowell slow the temperature reading?
Slightly. A close fit between bore and stem keeps the lag small; on HVAC lines it is rarely noticeable.
Can you supply thermowells for gauges we already have?
Yes. Send the stem diameter, length, connection thread and the pipe size.