The STD-T is Sitron's Pt100 temperature transmitter with a local LCD — the sensor, transmitter and display in one corrosion-resistant aluminium and stainless steel head, aimed at industrial process loops that want the reading where the probe is.

Why measure with a Pt100 element instead of a thermocouple in the loop?

For the -100 to +200 °C band that covers most process fluids, a platinum RTD is simply more stable and more linear than a thermocouple — no cold-junction correction, no millivolt drift, and a resistance that a transmitter converts with 0.1% accuracy and ±0.05% per-year stability. The STD-T drives the platinum element directly and puts the result on a 4–20 mA two-wire loop with HART, so the control system reads the same value the local display shows — and the 330° rotatable, backlit LCD with five 7-segment digits keeps the measured value visible in any mounting position.

What does a transmitter built into the head save at installation time?

A separate head transmitter and sensor means two junction boxes, two vendors and a field calibration step to match them. The STD-T arrives as one unit with an M12 connector, a choice of BSP, NPT, flange, sanitary or SAE process connections, and an aluminium over 316 stainless body sealed with Viton — so it mounts, wires and starts measuring in the time it takes to tighten the connector. Reverse-polarity, transient and surge protection ride along, IP66 keeps washdown out (IP67 on request), and an optional EEx ia IIC T4–T6 rating puts the same unit into hazardous areas.

• Pt100 input, range -100 to +200 °C, accuracy 0.1%
• 4–20 mA 2-wire with HART protocol
• 330° rotatable LCD, 5-digit backlit display
• Aluminium + 316 SS, IP66 / IP67, Viton seal, M12 connector
• Optional EEx ia IIC T4–T6, reverse-polarity and surge protected

Against a bare RTD that needs a separate transmitter and a display where neither exists, the STD-T delivers all three in one head — the reason process skids keep the temperature visible at the source.