EPR-IS

Supported Applications

The EPR-IS Series is the Easidew PRO I.S. intrinsically safe dew-point transmitter from Michell Instruments, a 2-wire instrument certified for trace-moisture measurement in hazardous-area gas processes. Its robust stainless-steel housing and global explosion-protection certification let it monitor dryness directly in classified zones where a spark or hot surface cannot be tolerated.

It is well suited to natural gas, refinery gases, hydrogen, nitrogen, air, and inert gas systems, and to petrochemical and CNG applications where continuous moisture control protects product quality, pipeline integrity, and downstream equipment. Delivered with a sintered guard as standard, the EPR-IS gives a reliable, certified moisture reading in demanding field conditions.

Operating Conditions & Performance

The transmitter measures dew point over -110 to +20°C (-166 to +68°F), with a companion range of -100 to +20°C (-148 to +68°F), resolving readings to 0.1 °C. It holds an accuracy of ±0.5 °C / ±0.9 °F with a repeatability of ±0.2 °C, and provides a typical T90 response of less than 10 seconds.

Output options include a 4–20 mA loop signal, a 0–10 V signal, and RS485 Modbus RTU, powered from 10–30 VDC into a load of 0–600 Ω through a terminal block and M20 x 1.5 gland. The sensor withstands pressures up to 52.5 MPa (525 barg / 7614 psig), and its wetted parts use 316L stainless steel with PTFE and silicone.

The EPR-IS carries an IP66 / NEMA 4X enclosure and tolerates vibration of 10–500 Hz at 1.5 mm (0.06 in) peak plus shock events of 11 ms duration. It operates over a process range of -100 °C to +100 °C, an ambient range of -40 °C to +85 °C, and storage to -40 °C to +85 °C. The probe measures 12 mm in diameter with a 50 mm insertion length, a 100 mm stem, and a 150 mm overall length. Hazardous-area certification includes ATEX/UKCA and IECEx (Ex d IIC T4 Gb), cQPSus (Class I, Division 1, Groups B, C, D, T4), plus Baseefa and QPS approvals.

Configuration Options

The EPR-IS is ordered as a configured transmitter with a simplified letter-based code, built on a common intrinsically safe platform supplied with a stainless-steel sintered guard. The configurable axes are:

• Range — a -100 to +20°C or -110 to +20°C dew-point range, or a non-standard configured range.
• Units — the analog scale can be expressed in °C or °F dew point, ppmV, or natural-gas moisture units, with a pressure value required for ppmV and natural-gas units.
• Oxygen cleaning — standard, or cleaned for oxygen service, which is offered only with the sintered guard.

Because the sensing platform, housing, and hazardous-area certification are shared across the series, the choices that change a delivered unit are the measurement range, the analog scaling units, and whether the wetted parts are cleaned for oxygen service.

Key Product Differences

Ordering follows the parent code and its feature positions, EPR-IS - <Range> - <Units> - <Oxygen Cleaning>. The lineup covers the letter combinations EPR-IS-AA, EPR-IS-AB, and EPR-IS-BA, for example:

• EPR-IS-AB — Easidew PRO I.S. 2-wire transmitter, ATEX certified, with the -100 to +20°C range and oxygen-cleaned wetted parts.
• EPR-IS-RA — non-standard range built to customer specification, with the range specified at time of order and no oxygen cleaning.

Under the previous ordering system the same choices were written out longhand, for example EPR-IS+(-100/+20C) + J1 for the ATEX-certified transmitter with the -100 to +20°C range, oxygen cleaned. Across every configuration the intrinsically safe sensor platform is unchanged — the model number simply records the chosen range, scaling units, and oxygen-cleaning options.