Applied Analytics OMA-406R Rackmount Process Analyzer

Overview

The Applied Analytics OMA-406R is the rackmount form of the OMA process analyzer, built to fit a standard 19-inch rack in an analyzer shelter, control room or laboratory. Like the rest of the OMA family it continuously measures chemical concentrations and physical properties that can be correlated with the absorbance spectrum, in the 200-800 nm UV-Vis band or the 400-1100 nm short-wave near-infrared band. Applied Analytics states that it can measure up to five chemicals in a liquid or gas stream, and that thousands of OMA-406 rackmount units have shipped since 1994.

Seven Star LLC supplies the Applied Analytics OMA-406R to refineries, gas processing plants, chemical producers and specialty gas fillers in the Sultanate of Oman and the GCC. Our engineers in Muscat review the analytes, ranges and sample conditions with you so that the flow cell, path length and wetted materials are specified correctly before the analyzer is built.

Measurement Principle of the Applied Analytics OMA-406R

The Applied Analytics OMA-406R uses dispersive absorbance spectrophotometry. White light from a pulsed xenon lamp travels through a fibre-optic cable to the sample flow cell, where a collimator narrows the beam. The light passes straight across the flowing process sample, picks up the absorbance imprint of its current chemical composition, and returns through a second collimator and fibre-optic cable to the nova II spectrophotometer. A holographic grating then disperses the light so that each wavelength falls on its own photodiode in a diode array.

The analyzer plots the lost light intensity at every wavelength to build a full absorbance spectrum, and its ECLIPSE software resolves the concentration of each analyte from that spectrum. Because many wavelengths are used instead of a single peak, overlapping compounds can be separated and noise at any one photodiode has little effect. The measurement cycle is described as virtually instantaneous, and Applied Analytics notes that new F₂ and Cl₂ readings are produced about every five seconds in excimer laser gas work.

Engineering Design of the Applied Analytics OMA-406R

A key safety point of the Applied Analytics OMA-406R is that no sample fluid enters the analyzer enclosure. The process stream stays in a dedicated stainless steel 316L flow cell on a separate flow cell panel, connected to the rackmount unit by two 600 µm core fibre-optic cables of 1.8 m as standard. The flow cell panel is customised per application, and the example in the datasheet uses two flow cells in series to obtain a longer optical path. The analyzer itself is a solid-state build with no moving parts, which keeps routine maintenance low.

The steel rackmount enclosure of the Applied Analytics OMA-406R measures 222 x 483 x 291 mm (8.75 x 19 x 11.46 in) and weighs 14 kg. It runs from 85 to 264 VAC at 47 to 63 Hz and draws 45 W. The operator uses the Applied Analytics standard HMI, an industrial controller with a touch-screen LCD running ECLIPSE runtime software, with data stored on a 256 GB solid-state drive. Where possible the analyzer is factory calibrated with certified calibration fluids, no recalibration is required after the initial calibration, and each measurement is normalised by Auto Zero.

Key Features of the Applied Analytics OMA-406R

The datasheet and product page highlight these features of the Applied Analytics OMA-406R.

• Continuous measurement of up to five chemicals in a liquid or gas stream from one spectrum.
• UV-Vis (200-800 nm) or SW-NIR (400-1100 nm) models to suit the analytes of interest.
• Fibre-optic design with a remote flow cell, so no sample enters the analyzer enclosure.
• Totally solid-state construction with no moving parts and a pulsed xenon lamp with an average five-year life.
• Repeatability of ±0.5% of scale and photometric accuracy of ±0.004 AU.
• Standard flow cell rated to 206 bar (3000 psi) and −20 to 150 °C sample temperature.
• Wetted material options including fused quartz, sapphire, BK7, Viton, FFKM, 316L stainless steel, Monel and Hastelloy.
• One isolated 4-20 mA output per analyte, two digital outputs for fault and sample-system control, and optional Modbus TCP/IP, RS-232, RS-485 or HART.

Industrial Applications

Applied Analytics describes the OMA-406 rackmount for specialty gas analysis, where its dispersive UV spectrophotometer measures fluorine, chlorine, hydrogen sulfide, sulfur dioxide, ammonia and other gas mixtures from ppm to percent levels, and a single analyzer can be calibrated for multiple ranges and analytes. Producers of excimer laser gas mixtures such as XeF or KrCl blends use it to quantify the halogen content of each cylinder during production and validation.

In Oman and the wider GCC the Applied Analytics OMA-406R suits applications where the analyzer should sit in a rack inside a shelter or laboratory while the flow cell stays close to the process: industrial and specialty gas filling stations, chemical plants in Sohar, and refinery or gas plant laboratories that need continuous measurement of H₂S, SO₂ or other UV-active compounds. Seven Star LLC supplies the Applied Analytics OMA-406R on request with engineering support in Muscat, and can coordinate the flow cell panel and sample conditioning with the manufacturer.

Technical Specifications

The following data are taken from Applied Analytics data sheet DS-002B (revised May 2026) for the Applied Analytics OMA-406R.

How to Order

For a quotation on the Applied Analytics OMA-406R, send Seven Star LLC the analytes and ranges, whether the stream is gas or liquid, the sample temperature and pressure, and the outputs your control system needs. We will confirm the configuration with the manufacturer, advise on lead time for Oman and the GCC, and the Applied Analytics data sheet can be downloaded from this page. Other OMA analyzers on our site include the Applied Analytics OMA-300 multi-stream process analyzer, the Applied Analytics OMA-206P portable analyzer and the Applied Analytics OMA chlorine analyzer.