EA2-OL

Supported Applications

The EA2-OL Series is the Easidew Online dew-point hygrometer from Michell Instruments, a two-part system pairing a dew-point sensor with a panel-mount monitor for continuous moisture measurement in industrial gas streams. Built around Michell's ceramic metal-oxide sensing technology, it delivers stable, repeatable readings and displays dew point or moisture content locally while also driving analog, digital, and alarm outputs.

The system suits natural gas, hydrogen, nitrogen, air, inert gases, and clean hydrocarbon applications where process dryness must be monitored and recorded. With a sampling block, dual programmable relay alarms, and Modbus RTU communications, the EA2-OL fits compressed-gas drying, process moisture control, and monitoring stations that need both a local readout and a signal to the wider control system.

Operating Conditions & Performance

The EA2-OL 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 / 0.1 °F. It holds an accuracy of ±0.5 °C / ±1.0 °F with a repeatability of ±0.2 °C and a typical T90 response under 10 seconds.

Output options include 4–20 mA and 0–10 V analog signals plus RS485 Modbus RTU, and the unit accepts either 10–30 VDC or 85–265 VAC power, driving up to a 500 Ω load on the current loop. The sensor handles operating pressure from 0 to 100 bar (0 to 1450 psi) with a burst rating of 300 bar (4350 psi), and its wetted parts use 316L stainless steel with PTFE and FKM/Viton elastomer.

The sensor carries an IP66 / NEMA 4X enclosure and tolerates vibration of 10–500 Hz at 1.5 mm amplitude plus shock events of 11 ms half-sine. It operates over a process range of -40 °C to +120 °C (-40 °F to +248 °F) and an ambient range of -20 °C to +60 °C (-4 °F to +140 °F), with storage to -40 °C to +70 °C (-40 °F to +158 °F). The probe measures 25 mm in diameter with a 50 mm insertion length and a 150 mm overall length, and the system is electrically safe to EN61010-1 with CE marking and traceable calibration.

Configuration Options

The EA2-OL is configured through a letter-based ordering code so the sensor, monitor, and cabling suit the installation. The configurable axes are:

• Range — a -100 to +20°C or -110 to +20°C dew-point range, or a non-standard configured range in °C, °F, or ppmV.
• Protection — a standard HDPE guard against fine particulates, or a stainless-steel sintered guard.
• Monitor — powered from 85 to 265 V AC or 24 V DC to match the available supply.
• Cable — a standard sensor cable in lengths of 0.8 m, 2 m, 5 m, or 10 m to reach between the sensor and monitor.
• Oxygen cleaning — standard, or cleaned for oxygen service, which is offered only with the sintered guard.

The choices that most change the delivered system are the monitor power option and the cable length, which together adapt the hygrometer to the panel supply and the physical distance to the sample point, while the guard and oxygen-cleaning selections govern particulate protection and media compatibility.

Key Product Differences

Ordering follows the parent code and its feature positions, EA2-OL - <Range> - <Protection> - <Monitor> - <Cable> - <Oxygen Cleaning>. The base configuration is EA2-OL-AAAAA, and the lineup extends across the letter combinations up to variants such as EA2-OL-BAAAA for the extended dew-point range.

Under the previous ordering system the base model was designated EA2-OL-HYG (Easidew Online Hygrometer, 2-wire, 1/8 DIN panel mount, with two alarms and a sampling block), with range, protection, monitor, cable, and oxygen-cleaning features called out by their own item codes. Across every configuration the sensing platform and monitor stay the same — the model number records the chosen range, guard, monitor power, cable length, and oxygen-cleaning options.