Southland Sensing OMD-677 Trace Oxygen Analyzer

Name: Southland Sensing OMD-677 Trace Oxygen Analyzer
Brand: Southland Sensing Ltd.

Description

Overview

The Southland Sensing OMD-677 is an online trace oxygen analyzer in a panel mount enclosure with an integral sample system. It is designed to measure oxygen in the sub 1 ppm region of a gas stream, and it is installed permanently in an analyzer panel or cabinet.

The lowest range is 0 to 1 ppm full scale with a resolution of 0.001 ppm. The analyzer can also be set to 0 to 10 ppm, 0 to 100 ppm, 0 to 1000 ppm and 0 to 25 % oxygen, in auto-range or manual-range mode. Sample gas is drawn from the process line through 1/8 inch compression tube connections and passes through the built-in flow control valve, sample and bypass valve and flow indicator before it reaches the sensor.

Operating Principle

The OMD-677 uses an electrochemical oxygen sensor based on the galvanic fuel cell principle. Oxygen in the sample gas reacts inside the cell and produces an electrical current that is proportional to the oxygen concentration. The electronics amplify this signal, apply digital temperature compensation and show the result on the backlit display in ppm or percent.

The sensor is self-contained. According to the manufacturer there is no need to clean electrodes or add electrolyte. The sensor is a consumable part, and the specification sheet states an expected sensor life of 20 to 25 months. The analyzer is calibrated periodically.

Two sensor types are listed for this analyzer. The standard TO2-133T trace oxygen cell is unaffected by background gases such as hydrogen, helium and hydrocarbons. The optional TO2-233T acidic cell is intended for samples that contain acid gases such as carbon dioxide, or for natural gas.

Engineering Design of the Southland Sensing OMD-677

The analyzer is built in a brushed stainless steel panel mount enclosure measuring 10.78 x 7.47 x 7.75 inches, with a weight of 12.0 lbs. The front panel carries the display, the keypad for the on-board menu, the flow control valve, the 4-way sample and bypass valve and the flow indicator. Southland Sensing states that the unit is designed as a direct fit field replacement for the Teledyne 3000TA and 3000TA-XL and for the AII GPR-1600, GPR-1600MS and PI2-MS-1000.

The bypass valve allows the sensor to be isolated from the sample line. The sample inlet pressure range is 0 to 50 psig and the stated flow range is 0.5 to 5 SCFH. The operating temperature range is 0 to 50 deg C and the power supply is 100 to 240 VAC.

Signal outputs include an isolated 4 to 20 mA output and 0 to 1 V DC and 0 to 10 V DC outputs, together with range identification outputs. Two adjustable Form C non-latching relay contacts can be configured as normally open or normally closed, as high or low alarms, with an optional delay. A separate Form C relay contact signals power failure. Bi-directional digital communication is provided by RS232 and Modbus RS485.

Key Features

Online trace oxygen analyzer with integral sample system
Low range 0 to 1 ppm with 0.001 ppm resolution, high range 0 to 25 %
Five ranges with auto-range or manual-range selection
Galvanic electrochemical sensor, standard TO2-133T or optional TO2-233T for acid gases
Flow control valve, 4-way sample and bypass valve and flow indicator on the front panel
Isolated 4 to 20 mA, 0 to 1 V DC and 0 to 10 V DC analog outputs
Two adjustable alarm relay contacts and one power fail relay contact
Bi-directional RS232 and Modbus RS485 communication
Panel mount brushed stainless steel enclosure, 100 to 240 VAC supply

Industrial Applications

Southland Sensing lists the following applications for the OMD-677:

Air liquefaction and air separation
Monitoring of pure gaseous hydrocarbon streams
Gas purity certification
Process monitoring of gaseous monomers
Semiconductor manufacturing
Protective atmosphere blanketing of feedstock

The sensor choice depends on the background gas, so the sample composition should be stated when the analyzer is specified.

Technical Specifications

Model	OMD-677
Type	Online trace oxygen analyzer, panel mount, with integral sample system
Analysis ranges	0 to 1, 10, 100, 1000 ppm and 0 to 25 % O2, auto-range or manual-range
Resolution	0.001 ppm
Accuracy	Better than +/- 1 % of full scale range, at constant conditions
Response time	T90 in 10 seconds
Sensor	TO2-133T trace O2 sensor, galvanic electrochemical fuel cell. Optional TO2-233T for acid gases
Sensor life	20 to 25 months
Sample system	Flow control, 4-way sample and bypass valve, flow indicator
Sample flow	0.5 to 5 SCFH
Inlet pressure	0 to 50 psig
Gas connections	1/8 inch compression tube
Analog outputs	Isolated 4 to 20 mA, 0 to 1 V DC, 0 to 10 V DC
Range ID	4 to 20 mA and 0 to 1 V DC analog outputs
Alarms	2 adjustable relay contacts, 1 power fail relay contact (Form C, non-latching)
Communication	Bi-directional RS232, Modbus RS485
Display	Large, with backlight
Temperature compensation	Digital
Operating temperature	0 to 50 deg C
Power	100 to 240 VAC
Enclosure	Brushed stainless steel, panel mount
Dimensions	10.78 x 7.47 x 7.75 inch
Weight	12.0 lbs
Calibration	Periodically
Manufacturer	Southland Sensing Ltd

Installation and Maintenance of the Southland Sensing OMD-677 Trace Oxygen Analyzer

Trace oxygen measurement in the ppm and sub-ppm range is very sensitive to air leaks, so the sample system matters as much as the analyzer itself. General good practice for an installation like the Southland Sensing OMD-677 trace oxygen analyzer includes:

Use clean, leak-tight stainless steel tubing and compression fittings for the sample line, and keep the line as short as practical to reduce response time.
Leak-test all connections after installation; even a small leak lets atmospheric oxygen into the sample and gives a falsely high reading.
Keep the inlet pressure and flow within the specified 0 to 50 psig and 0.5 to 5 SCFH, and vent the sample outlet to a safe location.
Use the bypass valve to isolate the sensor from the sample when the line is opened, to avoid exposing a trace sensor to air for long periods.
Calibrate periodically with a suitable certified span gas and, where required by the site procedure, a zero gas.
Plan sensor replacement around the stated 20 to 25 month sensor life, and keep a spare sensor of the correct type (TO2-133T or TO2-233T) for critical services.

Typical Applications in Oman & the GCC

Trace oxygen analyzers are used in the region’s industrial gas and air separation plants, nitrogen generation and inert gas blanketing systems, and in hydrocarbon processing where oxygen contamination of product or feed streams must be controlled. Where the sample contains carbon dioxide or is natural gas, the acid gas sensor option should be specified. The analyzer’s 0 to 50 °C operating range should be considered when it is installed in an outdoor analyzer shelter, which normally needs air conditioning in GCC summer conditions.

Request a Quote for Southland Sensing OMD-677 Trace Oxygen Analyzer

For the OMD-677 analyzer or any related control and instrumentation requirement, contact the Seven Star LLC team. Submit a formal inquiry through our RFQ page with your measurement range, background gas and sensor type, and our team will respond with a commercial proposal and the official OMD-677 documentation. The analyzer is supplied on request, lead time confirmed at quotation.

Related Products

Also available: Southland Sensing OMD-21 Portable Percent Oxygen Analyzer

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About brand

Southland Sensing Ltd. builds oxygen analyzers around oxygen sensors it makes in house, for trace and percent measurement. The analyzers carry the OMD name and come as portable units and as online instruments for panels and process lines.

Seven Star LLC lists Southland Sensing oxygen analyzers from the OMD series and supplies them, with replacement sensors, to gas plants, laboratories and process users in Oman.

Southland Sensing OMD analyzers listed here

Five OMD models are on this page:

OMD-21: portable percent oxygen analyzer
OMD-501X: 1/4 DIN panel mount analyzer with a remote sensor housing
OMD-625: online process analyzer for hazardous areas
OMD-677: online analyzer with ppm and percent ranges
OMD-190: oxygen analyzer

The measuring range and the sensor are part of the order, so state both with the OMD number.

Where Southland Sensing oxygen analyzers are used

Typical tasks are checking the purity of nitrogen and other inert gases, watching blanketing and purging, and monitoring glove boxes. Portable units serve spot checks, and online units stay on a sample line. Background gases matter: a stream that carries carbon dioxide or hydrogen sulfide needs a sensor suited to it, which is a frequent question from GCC gas processing sites.

Ordering Southland Sensing analyzers and sensors: what we need

Send the analyzer model and serial number, and for a sensor the type printed on the sensor label. For a new analyzer, tell us the measuring range you need, the background gas composition, the sample pressure and temperature, whether the unit must be portable or fixed, the power supply available, the outputs and alarms required, and the area classification of the mounting location. With this we check the sensor and analyzer selection against the manufacturer documentation. A sensor is a consumable with a limited life, so tell us if a spare sensor should be included.

Browse Southland Sensing Ltd. products by category: Gas Analyzer Systems.

Frequently Asked Questions

What is the Southland Sensing OMD-677?

It is an online trace oxygen analyzer in a panel mount, brushed stainless steel enclosure with an integral sample system. It measures oxygen in a gas stream down to the sub 1 ppm region, using a galvanic electrochemical sensor. It is a fixed process analyzer, not a portable flue gas tester.

What does the analyzer measure?

It measures oxygen concentration in a sample gas. The ranges are 0 to 1, 0 to 10, 0 to 100 and 0 to 1000 ppm and 0 to 25 %, selectable in auto-range or manual-range mode. Resolution is 0.001 ppm and the stated accuracy is better than +/- 1 % of full scale at constant conditions.

What sensor technology does it use?

It uses a galvanic electrochemical fuel cell made by Southland Sensing. The standard TO2-133T cell is unaffected by hydrogen, helium and hydrocarbon background gases. The optional TO2-233T acidic cell is intended for samples containing acid gases such as carbon dioxide, or natural gas. Stated sensor life is 20 to 25 months.

Where is the OMD-677 used?

The manufacturer lists air liquefaction and separation, monitoring of pure gaseous hydrocarbon streams, gas purity certification, process monitoring of gaseous monomers, semiconductor manufacturing and protective atmosphere blanketing of feedstock. It is installed in a panel and connected to the sample line with 1/8 inch compression tube fittings.

What details should I include in my inquiry for the Southland Sensing OMD-677 trace oxygen analyzer?

Send the model number, the background gas composition, the expected oxygen range, the sample pressure and the required quantity through the RFQ page. State whether acid gases such as carbon dioxide are present, because this decides between the TO2-133T and TO2-233T sensor. Seven Star LLC confirms the configuration and lead time at quotation.

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