--- title: Online Oxygen Analyser (Trace, % and Purity) url: https://www.sarveshanalytics.com/oxygen-gas-analyser.html description: ACCURRA-S oxygen analysers from ppm to 100 percent, electrochemical or paramagnetic, with pressure-compensated purity models. updated: 2026-11-03 source: html --- ACCURRA-S · Models 3015, 3030, 3090, 3130, 3190 # Online oxygen analysers from trace ppm to purity ACCURRA-S measures oxygen from 0 to 1000 ppm up to 100 percent, with the sensor matched to the range: electrochemical for trace, percent and the 3090 purity model, paramagnetic for 3130 percent and 3190 purity. Purity models 3090 and 3190 correct for ambient pressure and temperature. - ISO 9001:2015, certified by TÜV - Designed and built in Pune since 2002 - Supplied to Reliance, Tata Steel, Indian Oil, Linde and ISRO Quick answer ACCURRA-S oxygen models cover 0 to 1000 ppm (3015), 0 to 25 % (3030), 0 to 100 % (3130) and purity with compensation (3090 electrochemical over 0 to 100 %, 3190 paramagnetic over 95 to 100 %). The purity models correct for ambient pressure and temperature, reducing error to below 0.5 %. Updated 3 November 2026 · Figures from Sarvesh datasheets ## Why ACCURRA-S oxygen analysers ### Purity you can certify Models 3090 and 3190 correct for ambient pressure and temperature. A day and night pressure swing can cause up to 10 % error uncompensated; compensated, it stays below 0.5 %. ### The right sensor for the range Electrochemical cells for trace and percent oxygen, paramagnetic sensing with no consumable cell and a response below 5 seconds for percent and purity. ### Fast recovery at trace level A sensor bypass valve on 3015 isolates the cell during purging and upsets, so it returns to an accurate ppm reading quickly. ## Specifications | Item | Specification | Notes | |---|---|---| | 3015 | Trace, 0 to 1000 ppm (min 0 to 100 ppm) | Electrochemical; accuracy 1 % of reading +/- 2 ppm; T90 below 30 s | | 3030 | 0 to 25 % (min 0 to 5 %) | Electrochemical; accuracy +/- 0.01 % of FS; T90 below 20 s | | 3090 | Purity, 0 to 100 % (min 0 to 5 %) | Electrochemical, pressure and temperature compensated; accuracy +/- 0.1 % of FS; T90 below 20 s | | 3130 | 0 to 100 % (min 0 to 5 %) | Paramagnetic; accuracy +/- 0.1 % of FS; T90 below 5 s; no internal sample pump | | 3190 | Purity, 95 to 100 % | Paramagnetic, compensated; accuracy +/- 0.5 % of FS; T90 below 5 s; no internal sample pump | | Purity error | Below 0.5 % with compensation | Up to 10 % uncompensated over a day and night pressure swing, per the catalogue | From the current Sarvesh product datasheets and company profile. Specifications may change without notice as products improve. The final responsibility to check that a product meets the process and analyser requirement remains with the customer. ## Which model for which range | Model | Measures | Range | Sensor | Notes | |---|---|---|---|---| | 3015 | Trace oxygen in N2, Ar, He, H2 | ppm | Electrochemical | Nitrogen plants, blanketing, furnace atmospheres | | 3030 | Percent oxygen | 0 to 25 % | Electrochemical | Process monitoring, fermenters, inerting | | 3130 | Percent oxygen, fast response | 0 to 100 % | Paramagnetic | PSA oxygen, pressurised lines | | 3090 | Oxygen purity | 0 to 100 %, compensated | Electrochemical | Air separation, PSA and medical oxygen, filling | | 3190 | Oxygen purity | 95 to 100 %, compensated | Paramagnetic | Air separation, cryogenic oxygen, filling | ## Key features - Dual-channel pairings such as O2 ppm with dew point, with CO or CO2, or O2 percent with CO or CO2 - Sensor bypass valve on 3015 so the cell recovers quickly after purging - Isolated dual-range 4-20 mA, failsafe alarms and Modbus RTU over RS 485 ## How it works Electrochemical cells suit trace and percent oxygen, are compact, and need no reference gas, which makes them the default for ppm-level nitrogen and argon. Paramagnetic sensors exploit oxygen's attraction to a magnetic field, and are preferred for percent-level measurement and for purity near 100 percent. High-purity oxygen readings depend on barometric pressure. A 5 percent fall in pressure lowers the oxygen partial pressure by 5 percent even though the gas is as pure as before, and the catalogue notes up to 10 percent error over a day and night swing above 90 percent oxygen. Models 3090 and 3190 measure ambient pressure and temperature and correct for them, which reduces the error to below 0.5 percent. ## Requirements and limits - Safe-area analyser; the sample should be non-corrosive, non-toxic, non-flammable and dry. - No internal sample pump on 3015, 3130 and 3190. ## On site: utilities and calibration gases What to have ready at your plant before installation and commissioning. | Item | Requirement | Notes | |---|---|---| | Power at the analyser | 100 to 240 V AC, 50/60 Hz, 45 W | | | Zero gas | Zero-grade nitrogen, 99.9999 % | 10 litre cylinder with regulator | | Span gas, trace oxygen | Oxygen in nitrogen near the top of the range, for example 1000 ppm | 10 litre cylinder with regulator | | Span gas, 3090 | Zero-grade oxygen; zero on zero-grade nitrogen | | | Span gas, 3190 | Zero-grade oxygen; zero on 95 % oxygen in nitrogen | | | Instrument air and service nitrogen | 4 kg/cm² minimum | | | Sample at the analyser | 2 to 10 psig, about 1 LPM, 5 to 45 °C, dust below 3 micron | Pressure and flow regulated by the user | | Mounting | 19 inch rack or panel, in a safe area | | ## Selection guidance Choose 3015 for nitrogen purity, blanketing and furnace atmospheres. Choose 3030 or 3130 for percent oxygen. Choose 3090 or 3190 when oxygen purity is a product specification. For percent oxygen in a hazardous area see ACCURRA-Hz and INFINITY-Tx; for flue gas, ACCURRA-Zr. ## Applications Application pages where this is part of the recommended solution: - [Autoclaves](https://www.sarveshanalytics.com/applications/autoclave-oxygen-measurement.html) - [Oxygen purity in air separation plants](https://www.sarveshanalytics.com/applications/oxygen-purity-air-separation-plant.html) - [Medical oxygen plant purity monitoring](https://www.sarveshanalytics.com/applications/medical-oxygen-plant-purity-monitoring.html) - [Nitrogen purity and trace oxygen](https://www.sarveshanalytics.com/applications/nitrogen-purity-trace-oxygen.html) - [Nitrogen blanketing and inerting](https://www.sarveshanalytics.com/applications/nitrogen-blanketing-and-inerting.html) - [Closed-loop dryers and spray dryers](https://www.sarveshanalytics.com/applications/closed-loop-and-spray-dryer-oxygen-safety.html) - [Fermenter and bioreactor off-gas](https://www.sarveshanalytics.com/applications/fermenter-and-bioreactor-off-gas.html) - [Welding and laser gas mixtures](https://www.sarveshanalytics.com/applications/welding-and-laser-gas-mixtures.html) ## Compatible products [ ### ACCURRA-S Online analyser for trace, percent and purity O2, CO, CO2, CH4 and dew point; can measure two gases from one sample. View ACCURRA-S ](https://www.sarveshanalytics.com/safe-gas-analyser.html)[ ### ACCURRA-Hz Process gas analyser in an enclosure certified for Gas Group IIC, Zone 1 and 2, T6. View ACCURRA-Hz ](https://www.sarveshanalytics.com/hazardous-gas-analysers.html)[ ### INFINITY-Tx Loop-powered two-wire transmitter for percent O2 and trace CO in hazardous areas. View INFINITY-Tx ](https://www.sarveshanalytics.com/oxygen-transmitter.html)[ ### SV-200 / SV-400 vaporisers Sample vaporisers for cryogenic and wet samples with no loss of sample. View SV-200 / SV-400 vaporisers ](https://www.sarveshanalytics.com/sample-vaporisers.html) ## Frequently asked questions **What is the difference between 3090 and 3190?** Both are purity models with ambient pressure and temperature compensation. 3090 uses an electrochemical sensor over 0 to 100 percent; 3190 uses a paramagnetic sensor over 95 to 100 percent, with a response below 5 seconds. **What range for 99.99 % nitrogen?** Use trace model 3015. 99.99 percent nitrogen allows up to 100 ppm of impurity, so 0 to 100 or 0 to 1000 ppm is typical. **Why does pressure matter for oxygen purity?** The sensor responds to the amount of oxygen it sees, which depends on pressure. Compensation corrects the reading to the true percentage. **Can I measure oxygen in hazardous areas?** Yes, with ACCURRA-Hz or the INFINITY-Tx transmitter. ## Related pages - [ACCURRA-S](https://www.sarveshanalytics.com/safe-gas-analyser.html) - [ACCURRA-S carbon monoxide analysers](https://www.sarveshanalytics.com/carbon-monoxide-gas-analyser.html) - [ACCURRA-S carbon dioxide analysers](https://www.sarveshanalytics.com/carbon-dioxide-gas-analyser.html) - [ACCURRA-S methane analyser](https://www.sarveshanalytics.com/methane-gas-analyser.html) - [ACCURRA-S M015 moisture analyser](https://www.sarveshanalytics.com/trace-moisture-analyser.html) - [ACCURRA-Hz](https://www.sarveshanalytics.com/hazardous-gas-analysers.html) - [Hazardous-area oxygen analyser](https://www.sarveshanalytics.com/hazardous-oxygen-analyser.html) - [INFINITY-Tx](https://www.sarveshanalytics.com/oxygen-transmitter.html) - [Hazardous-area hydrogen analyser](https://www.sarveshanalytics.com/hazardous-hydrogen-gas-analyser.html) - [Hazardous-area moisture analyser](https://www.sarveshanalytics.com/hazardous-moisture-analyser.html) - [ACCURRA-Zr](https://www.sarveshanalytics.com/flue-gas-analysers.html) - [ACCURRA model numbers](https://www.sarveshanalytics.com/accurra-model-numbers.html) - [**Browse all gas analysers**](https://www.sarveshanalytics.com/gas-analyser.html)