Cambridge Sensotec Ltd - Cambridge Sensotec: Advancing Excellence in Gas Analysis

SF6 is a man-made gas used in high-voltage switchgear because of its great arc quenching capabilities. Partial discharges and leaks over time eventually cause the SF6 to decompose into highly corrosive compounds. It is therefore essential to monitor the condition of the SF6 to protect the equipment from spark damage and corrosion.

The Rapidox 3100C IR is a multi-gas analyser for the simultaneous measurement of SF6 (0-100%), SO2 (0-100ppm) and dew-point (-65+20°C). The analyser is designed for controlling and monitoring the quality of SF6 in gas insulated sub-stations and circuit breakers. The analyser not only measures the SF6 gas content in air or nitrogen over the full range, but also measures the moisture content of the SF6 which is essential when monitoring the dielectric strength of the gas. The decomposition products of SF6 can be identified by analysing the SO2 content of the gas; this forms from the breakdown of SOF2 and SOF4 after an electrical discharge. The analyser incorporates an electrochemical SO2 sensor to measure ppm levels of sulfur dioxide. All three gases can be monitored and data-logged simultaneously and just a few minutes are required to get a stable reading.

Regular checking of SF6 gas insulated substations allows fault preventative maintenance programs to be implemented, and increases the life cycle of the SF6. The analyser has a gas output nozzle allowing all sampled gas to be recovered and
recycled, ensuring that no SF6 gas is released into the atmosphere (in accordance with the Kyoto agreement). Fully compatible with SF6 gas recovery systems. The Unit can be supplied with optional transport Features Peli-case & thermal printer

Cambridge Sensotec Rapidox 1100EF gives the use continuous oxygen analysis from 0-100% O2 in steps of 0.1%. It is a very accurate device with a typical response time of 10 seconds for a 90% step change in gas compositions.
At the heart of the Rapidox 1100EF is a Yuasa electrochemical oxygen sensor, which has a five year life expectancy and can be used in a wide range of gases such as nitrogen, argon, helium, carbon dioxide. The sensor is not affected by the presence of hydrocarbons.

The analyser contains a powerful diaphragm pump that constantly draws a gas sample at a flow rate of approximately 1 litre per minute. An on-board pressure sensor compensates for any pressure fluctuations in the sample gas
The analyser includes fully programmable alarm circuits (alarm LOW and HIGH), programmablen analogue outputs (0-10V and 4-20mA), easy calibration (user selectable gases), RS232 communications and a full set of communications / data-logging software.

The Rapidox 2100ZF portable oxygen gas analyser is packed with features normally only available in oxygen analysers costing thousands of pounds. From the display to the outputs, all features are fully user-programmable using the keypad on the front panel. Easy to use and simple to calibrate using your choice of gases, the Rapidox offers exceptional performance and flexibility using a rugged, long-life zirconia oxygen sensor. The Rapidox comes with Windows software for easy data-logging and graphing.

The Rapidox 2100ZF allows fast and accurate oxygen analysis over the full oxygen range
(10e-20ppm to 100% O2) using a zirconia sensor supplied on 2m cable (extension cables available). The analyser provides continuous on-line oxygen analysis, with a typical response time less than 4 seconds for a 90% response to a step change in gas compositions. The sensor is especially useful for high temperature oxygen measurements and in vacuum conditions, where a range of vacuum fittings are offered. Type K thermocouple input is included as standard for independent temperature measurements up to 1250°C

Standard features include fully programmable alarm circuits, programmable analogue outputs (0-5V & 4-20mA), easy calibration (user selectable gases), RS232 / RS485 communications and a full set of communications / data-logging software that is compatible with MS-Excel.
The auxiliary input can be used to connect an optional pressure / vacuum / dewpoint sensor which can be displayed and data-logged simultaneously.

The Rapidox 3100ZA dual gas O2 / CO2 analyser allows fast and accurate oxygen analysis over the full oxygen range (10e-20ppm to 100% O2) and a range of CO2 concentrationsup to 100%. The analyser provides continuous on-line analysis, with a typical response time less than 5 seconds for a 90% response to a step change oxygen gas compositions and 30 seconds for a 90% change in CO2 concentration. At the heart of the Rapidox 3100ZA is a top-of-the-range linear-piston vacuum pump manufactured by Nitto; a world leader in pump technology. The pumps are exceptionally quiet (40 dB/m or less). The flow of gas can be adjusted using the flow gauge / needle valve on the front panel of the analyser. Typical flow rate is 1 litre per minute.

The oxygen sensor head is located inside the analyser and comprises a zirconia ceramic tube that needs to be heated to 650°C before it will conduct oxygen ions. An internal pressure sensor compensates for small changes in gas pressure to keep the readings stable. The CO2 sensor is based on infra-red NDIR silicon based chip technology with unique internal referencing. The module is exceptionally stable and requires no maintenance or calibration.

The analyser is packed with features including fully programmable alarm circuits, programmable analogue outputs, easy calibration (user selectable gases), RS232 / RS485 communications, independent type K thermocouple and a full set of communications / data-logging software. Full data logging of O2 & CO2 together with temperature and pressure is possible using the MS-Excel compatible logging software.

The Rapidox 3100ZD dual gas O2 / H2O (moisture) analyser allows fast and accurate oxygen analysis over the full oxygen range (10e-20ppm to 100% O2) and a range of H2O concentrations (measured in terms of dew-point) from -65°C to +20°C dp. The analyser provides continuous on-line analysis, with a typical response time less than 5 seconds for a 90% response to a step change oxygen gas compositions and 30 seconds for dew-point. The dew-point sensors are OEM modules provided by either Michell Instruments or Alpha Moisture depending on range requested.

At the heart of the Rapidox 3100ZD is a top-of-the-range linear-piston vacuum pump manufactured by Nitto; a world leader in pump technology. The pumps are exceptionally quiet (40 dB/m or less). The flow of gas can be adjusted using the flow gauge / needle valve on the front panel of the analyser. Typical flow rate is 1 litre per minute. The oxygen sensor head is located inside the analyser and comprises a zirconia ceramic tube that needs to be heated up to 650°C before it will conduct oxygen ions. An internal pressure sensor compensates for small changes in gas pressure to keep the readings stable. The dew-point sensors are high precision transmitters that are fully factory calibrated and is supplied with its own Calibration Certificate, providing direct traceability to both UK (NPL) and US (NIST) Humidity Standards The sensor is certified at thirteen dew-point levels across its operating range against a certified reference hygrometer, using a mass-flow humidity generator system as a source of reference calibration gas.

The analyser is packed with features including fully programmable alarm circuits, programmable analogue outputs, easy calibration (user selectable gases), RS232 / RS485 communications, independent type K thermocouple and a full set of communications / data-logging software. Full data logging of O2 & H2O together with temperature and pressure is possible using the MS-Excel compatible logging software

Cambridge Sensotec have revised and greatly improved the Rapidox gas recovery bag to meet the harsh demands of the industrial gas recovery sector. The Rapidox gas recovery bag is designed for the collection of SF6 and many other gases from any compatible gas analyser including the Rapidox 3100-C IR SF6 multigas analyser. The new design is made from extremely tough DP472 PU (712028) coated polamide material and has a safety blow off valve incorporated. It also has a strong rope reinforced carry handle for enhanced portability. The second generation of the gas recovery bag is designed to meet a set of rigorous specifications and manufactured in the United Kingdom.

Since the signing of the Kyoto treaty any discharge of SF6must be contained and recovered or recycled. This is because SF6 is a green house gas with global warming potential that is 23000 times that of CO2. The Rapidox gas recovery bag, which has a maximum volume of 80 litres, enables the user to quickly and efficiently sample multiple sites and ensure that no SF6 escapes into atmosphere. The contents of the bag can either be decanted into a permanent storage bottle or into a recovery / recycling system. Using the recovery bag in conjunction with a Rapidox 3100-C IR SF6 multigas analyser allows Cambridge Sensotec’s customers to run cost saving condition based maintenance programs.

Cambridge Sensotec supplies products for safety, industrial, control, welding, medical and diving applications, including:

• BW Honeywell: Safety gas detectors
• Witt Gas: Gas sensors and leak detectors for MAP
• Industrial Scientific Oldham: Gas detectors personal and area protection for Toxic, Explosive and Safety
• Viamed: Medical oxygen gas monitors
• Vandagraph: Diving gas analysers