MI Michell Instruments Ltd.

Pura Trace Moisture Transmitter

Name: Pura Trace Moisture Transmitter
Brand: Michell Instruments Ltd.
SKU: MI-PURA-TX

Standalone trace-moisture transmitter for ultra-high-purity gas, down to 1 ppbV.

ModelPura

SKUMI-PURA-TX

CategoryDew Point & Moisture

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Key Features

Measures down to −120°Cdp (−184°Fdp), <1 ppbV
Traceable 7-point calibration certificate
4-20 mA 2-wire or 3-wire output; M12 variant: Modbus RTU/RS485
1/2" or 1/4" male VCR process connections
MiniDIN 43650 C or M12 5-pin electrical connectors
Optional intrinsically safe (I.S.) approved variant
Clean-room double-bagged or industrial single-bagged packaging
Reconfigurable via Easidew and Pura communications kit

Overview

The Pura is a small, rugged standalone trace-moisture transmitter for ultra-high-purity gas applications, measuring dew point down to −120°Cdp (under 1 ppb). Unlike the Pura Online, it is supplied as a transmitter only (no local display/monitor), for direct integration into existing plant control or DCS systems via analog or digital output.

Working Principle

A ceramic metal-oxide sensor in a cold-drawn, electropolished stainless-steel body measures trace moisture in ultra-pure gas streams. The transmitter outputs 4-20 mA (2-wire or 3-wire) or, on the M12 digital variant, Modbus RTU over RS-485, for direct connection to existing control systems without a dedicated local monitor.

Applications

Benefits

Direct integration into existing control/DCS systems without an extra local display
Electropolished sample path suited to ultra-high-purity gas integrity
Hazardous-area variant available without changing sensor technology
Sensor exchange program keeps ultra-pure gas line downtime near zero

Technical Specifications

Performance
Measurement Range	−120 to −40°Cdp (non-standard on request)
Accuracy	±1°C (−40 to −60°C); ±2°C (−60 to −100°C); ±4°C (−100 to −120°C, extrapolated)
Calibration	Traceable 7-point certificate

Electrical
Output	4-20 mA 2-wire or 3-wire (M12: + Modbus RTU/RS485)
Scaled Range	Dew point: −120 to −40°C; Moisture: 0–127 ppmV
Supply Voltage	12–28 Vdc (2-wire/3-wire/I.S.); 5–28 Vdc (M12 digital)
Load Resistance	Max 250Ω @14V (500Ω @24V)
Current Consumption	23 mA max
Compliance	CE & UKCA

Operating
Operating Temp	−40°C to +60°C
Compensated Range	−20°C to +50°C
Operating Pressure	10⁻⁷ Pa min; 24 MPa (240 barg) max
Flow Rate	1–5 Nl/min (sample block); 0–10 m/s direct insertion

Mechanical
Housing	316 stainless steel
Ingress Protection	IP66 (MiniDIN); IP65 (M12)
Process Connection	2x 1/4" male VCR (Premium/OEM); 1/2" male VCR (Sensor)
Weight	450 g (Premium/OEM); 180 g (Sensor version)

Hazardous Area (I.S. Variant)
ATEX / UKCA	II 1 G Ex ia IIC T4 Ga
IECEx	Ex ia IIC T4 Ga
North America	cQPSus Class I Div.1 Groups A-D T4

Downloads

Datasheet (PDF)PDF

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Frequently Asked Questions

What warranty is offered on this product?

All Tetracon-supplied instruments carry the original manufacturer warranty (typically 12–24 months) plus first-line local support from our Islamabad service centre.

Do you provide installation and commissioning?

Yes. Our manufacturer-trained engineers offer on-site installation, commissioning and startup training anywhere in Pakistan.

Are spares and calibration available locally?

Common spares are held in local stock. Calibration is available at our lab or on-site with NIST-traceable reference standards.

How long is the typical lead time?

Stocked items ship within 3–5 working days; engineered configurations typically 6–10 weeks depending on manufacturer schedule.

Request a Quote — Pura Trace Moisture Transmitter

Complete the form below and one of our engineers will respond within 1 working day with pricing and lead time. Prefer email? Contact our sales team.