How do you add a reliable temperature measurement point to a machine that has almost no room left for one? Designers of compressors, generator sets, HVAC-R units and skid packages face this question constantly. The answer is often a PT100 transmitter small enough to thread directly into the process and still deliver a clean 4–20 mA signal. The Paquin P58 PT100 Temperature Transmitter was designed for exactly that role. Paquin describes it as one of the most compact PT100 transmitters on the market, and it still offers Class A accuracy, a user-configurable range and a rugged 316L stainless or thermoplastic housing.
Where conventional temperature assemblies fall short
A traditional temperature point often combines a sensing element, a thermowell, a connection head and a separate transmitter. That arrangement works well in a process plant with plenty of pipe rack. On a compact machine, however, it can be difficult to fit, adds weight and introduces more parts to install and maintain.
OEMs also tend to build several variants of the same machine, and each one may need a different temperature range. If every range requires its own part number, inventory grows and ordering becomes more complicated. A sensor that is small, self-contained and adjustable after purchase addresses both problems.
A closer look at the P58 PT100 transmitter
The P58 combines a PT100 element, signal conditioning electronics and an M12 connector in a single compact body.
- Very small and light. The thermoplastic version has a body length of roughly 50 mm and a 15 mm diameter. Weight is about 20 g with the 13 mm probe.
- Class A accuracy. The PT100 element is Class A according to IEC 751. At 77°F, accuracy is the greater of ±0.1 K or ±0.1% of span, and long-term stability is within 0.1% of span per year.
- Fast response. The P58 responds to a temperature change in less than 3.5 seconds. An input filter can be set between 0.4 and 9.4 seconds to smooth noisy readings.
- Two housing options. Choose 316L stainless steel for demanding environments or a durable thermoplastic housing for lighter-duty installations. Wetted parts are AISI 316L either way.
- Sealed for industrial use. The P58 is rated IP67 and tolerates 0–100% humidity.
- Wiring protection. Reverse polarity protection is built in.
Set the range yourself with the PSRC1 kit
Every P58 ships calibrated to a factory default range of 0 to 212°F, or to a custom range specified at the time of order. With the optional PSRC1 Range Configuration Kit, users can re-scale the zero point and span anywhere within -58 to +230°F. The kit connects to a Windows PC by USB and needs no additional power source, so ranges can be adjusted at the bench or during commissioning.
For OEMs, this flexibility means a single P58 configuration can serve several machine variants, with the final range set during assembly.
Fault signals your controller can act on
A temperature transmitter should never report a plausible-looking value when something has gone wrong. The P58 follows NAMUR NE43 fault signaling. A broken sensor drives the output to 21 mA, and a short circuit drives it to 3.6 mA. Both values fall outside the normal 4–20 mA band, so a controller can recognize them as faults. Using the configuration kit, each fault value can be switched to suit your control logic. A reversed 20–4 mA output is also available.
Applications
- Generators
- Compressors
- HVAC-R systems
- CNC machines
- Skid packages
- Test benches
Key specifications (snapshot)
| Parameter | Value |
|---|---|
| Sensing element | PT100, Class A per IEC 751 |
| Accuracy (at 77°F) | Greater of ±0.1 K or ±0.1% of span |
| Long-term stability | Max. 0.1% of span per year |
| Temperature influence (from 20°C / 68°F) | Greater of ±0.3°C or ±0.3% of span per 25°C change (±0.54°F or ±0.3% of span per 45°F) |
| Response time | <3.5 seconds |
| Measurement range | -58 to +230°F (factory default 0 to 212°F; user-configurable with PSRC1) |
| Maximum media temperature vs. ambient | 230°F at 77°F ambient; 203°F at 122°F; 185°F at 185°F |
| Electronics operating range | -40 to +185°F |
| Output | 4–20 mA or 20–4 mA |
| Supply voltage | 5.5–32 VDC |
| Maximum load | 840 Ω at 24 VDC |
| Fault signaling | NAMUR NE43 (sensor break 21 mA; short circuit 3.6 mA; configurable) |
| Ingress protection | IP67; 0–100% humidity |
| Housing | 316L stainless steel or thermoplastic |
| Wetted parts | AISI 316L |
| Process connection | 1/8" NPT male or G 1/8" male |
| Electrical connection | M12x1, 4-pole male |
| Probe length | 13, 24 or 35 mm standard; custom lengths up to 1,500 mm (49") |
Full technical parameters, wiring and dimensional drawings are available in the P58 datasheet (PDF).
Options, accessories and quotes
A P58 part number is built from a short list of choices: housing material, process connection, probe length, output direction and calibrated range. Probes longer than the 35 mm standard can be made to order up to 1,500 mm. M12 mating cables are available in straight and 90° versions from 1 to 20 meters, along with a field-wireable connector. The PSRC1 kit is quoted separately. If your control system calls for a voltage signal instead, the P59 PT1000 transmitter with 0–10 VDC output is a close companion to the P58.
Because pricing depends on the configuration, the quickest route is a direct request. Tell us about your machine using the quote form on the P58 product page. Include your temperature range, probe length and preferred housing, and a Paquin specialist will return pricing for that exact build.
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