ACCURRA-S Safe Area Gas Analyser

Quick answer

ACCURRA-S is Sarvesh's safe-area online gas analyser for oxygen, CO, CO2, methane and moisture, from ppm to 100 %. It has a 4-20 mA output, failsafe relays and Modbus, and expects a dry, non-corrosive, non-toxic, non-flammable sample at 2 to 10 psig.

Updated 3 November 2026 · Figures from Sarvesh datasheets

Why ACCURRA-S

Accurate from ppm to purity

Trace oxygen to 1 % of reading ±2 ppm; purity oxygen compensated for ambient pressure and temperature, which keeps error below 0.5 %.

Integrates without add-ons

Dual-range isolated 4–20 mA with range ID relay, six failsafe relays, Modbus RTU and output freeze during calibration come as standard.

Maintenance you can plan

Time-stamped calibration, alarm and fault history shows drift and residual sensor life, so consumable sensors are replaced on schedule.

Specifications

Item	Specification	Notes
Display	Backlit LCD, 4 lines x 20 characters
Analog output	1 x 4-20 mA isolated, max load 500 ohm, dual range	Range freely selectable over the full measurement range
Relays	6 x SPST rated 1 A 230 V AC, all failsafe	Alarm 1, Alarm 2, fault, sample pump or range ID, two for auto-calibration valves
Communication	Modbus RTU over RS 485	Read measured value, status, set-up and history; write auto-calibration
Enclosure	19 inch rack or panel; 134 H x 483 W x 180 (short) or 280 (long) D mm	IP 20, safe area only; net about 6 kg, gross about 8 kg
Power	100 to 240 V AC, 50/60 Hz, 45 W
Inlet and outlet	1/4 inch OD SS316
Ambient	5 to 40 C; below 90 % RH non-condensing	Storage 0 to 50 C

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.

Models and ranges

Model	Measures	Range	Sensor	Notes
3015	Oxygen, trace	0 to 1000 ppm (min 0 to 100 ppm)	Electrochemical	Sensor life above 18 months; sensor bypass valve supplied
3030	Oxygen, percentage	0 to 25 % (min 0 to 5 %)	Electrochemical	Sensor life above 2 years
3090	Oxygen, purity	0 to 100 % (min 0 to 5 %)	Electrochemical, ambient pressure and temperature compensated	Sensor life above 2 years
3130	Oxygen, percentage	0 to 100 % (min 0 to 5 %)	Paramagnetic	No consumable sensor; no internal sample pump
3190	Oxygen, purity	95 to 100 %	Paramagnetic, ambient pressure and temperature compensated	No consumable sensor; no internal sample pump
2015	Carbon monoxide	0 to 1000 ppm (min 0 to 100 ppm)	Electrochemical cell	Sensor life above 2 years
2030	Carbon monoxide	0 to 100 % (min 0 to 5 %)	NDIR	Sensor life above 5 years
6015	Carbon dioxide	0 to 5000 ppm (min 0 to 100 ppm)	NDIR	Sensor life above 5 years
6030	Carbon dioxide	0 to 20 % or 0 to 100 % (min 0 to 5 %)	NDIR	Sensor life above 5 years
4030	Methane	0 to 100 % (min 0 to 5 %)	NDIR	Sensor life above 5 years
M015	Moisture / dew point	-80 to +20 C dp (min -80 to 0 C dp)	Ceramic sensor	Sensor bypass valve supplied; field calibration not possible

Performance by model

Model	Range and resolution	Intrinsic error (accuracy)	Repeatability	Response T90
3015	0 to 1000 ppm, resolution 0.1 ppm	1 % of reading +/- 2 ppm	Zero +/- 2 ppm; span 1 % of reading	Below 30 s
3030	0 to 25 %, resolution 0.01 %	+/- 0.01 % of FS	+/- 0.04 %	Below 20 s
3090	0 to 100 %, resolution 0.01 %	+/- 0.1 % of FS	+/- 0.5 %	Below 20 s
3130	0 to 100 %, resolution 0.01 %	+/- 0.1 % of FS	+/- 0.1 % of FS	Below 5 s
3190	95 to 100 %, resolution 0.01 %	+/- 0.5 % of FS	+/- 0.5 % of FS	Below 5 s
M015	-80 to +20 C dp, resolution 1 C	+/- 2 C dp	1 C dp	2 min at 5 LPM, dry to wet
2015	0 to 1000 ppm, resolution 0.1 ppm	1 % of FS	Zero +/- 2 ppm; span +/- 10 ppm	Below 30 s
2030	0 to 100 %, resolution 0.01 %	2 % of FS	2 % of reading	Below 30 s
6015	0 to 5000 ppm, resolution 0.1 ppm	1 % of FS	Zero +/- 10 ppm; span +/- 50 ppm	Below 60 s
6030	0 to 20 % or 0 to 100 %, resolution 0.01 %	+/- 1 % of FS	+/- 0.05 %	Below 60 s
4030	0 to 100 %, resolution 0.01 %	2 % of FS	2 % of reading	Below 45 s

Key features

Dual-channel: two different sensors in series, each with its own electronics, current output, relays and Modbus ID
Two independent failsafe alarm relays, configured as Lo-LoLo, Lo-Hi or Hi-HiHi
Dual-range 4-20 mA output with a range ID relay, useful when start-up readings are high
Output freeze: outputs hold their last value during calibration check, calibration and auto-calibration
Sensor bypass valve on trace oxygen and dew point models, to isolate the sensor during purging or upsets
Optional internal solenoid valves for auto-calibration, started from the keypad, a cyclic timer or Modbus
Calibration, alarm and fault history; last calibration with deviation values supports audits
Password-protected calibration, set-up and diagnostics; built-in hardware diagnostic mode

How it works

Each ACCURRA-S sensor has its own electronics and microcontroller, which makes the hardware independent. A dual-channel unit houses two sensors in series, with common pneumatics, so you measure two gas components in one sample with separate outputs, relays and Modbus addresses. A fault in one channel does not stop the other.

The analyser is designed to be easy to integrate: an internal fine filter of glass micro fibre, a flow indicator and, on trace oxygen and dew point models, a sensor bypass valve. The sample handling between your process and the analyser decides years of trouble-free performance, so the catalogue states the sample conditions that ACCURRA-S expects.

Requirements and limits

The sample gas should be non-corrosive, non-toxic, non-flammable, non-condensing and dry, and free from entrained oil.
Sample pressure 2 to 10 psig maximum, regulated externally. Recommended flow 1 LPM.
Dust or particulate below 3 micron; the built-in fine filter handles light loads, and heavier dust needs an upstream filter.
Materials in contact with sample: SS316, Viton, PTFE, glass, aluminium and acrylic.
Sample temperature 5 to 45 C, and a sample dew point at least 5 C below the lowest ambient temperature.
Auto-calibration is not available on 3015 and M015, and on dual-gas units the calibration valves are external (relay outputs only). An internal sample pump is not available on 3015, M015, 3130, 3190 or any dual-gas unit. When the pump option is chosen, the range ID relay is unavailable.
Field calibration is not possible on the dew point model M015.
If your sample does not comply, we design a conditioning system around your application; flammable or toxic gas is reviewed case by case.

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
Span gas, percent CO, CO₂ or CH₄	Zero-grade CO, CO₂ or CH₄, 99.999 %
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

Options and ordering

Ordering code: first and second component gas (model numbers above); auto-calibration as none, relay output only, or internal solenoid valves; relay 4 as range ID, internal sample pump or relay for an external pump; AC power
Sample conditioning: SGI-300 cooler, i-Cons complete sampling system, SP-300 heated probe, filters, scrubbers and catchpots

Selection guidance

Choose ACCURRA-S for purity measurement, gas certification, trace impurities, process monitoring in oxygen, nitrogen, argon and CO2 plants, welding gases, fermenter off-gas and furnace atmospheres.

For binary gases such as hydrogen, helium and argon, see the ACCURRA-TCD pages. For hazardous areas see ACCURRA-Hz. For percent oxygen in a flue duct see ACCURRA-Zr.

Applications

Application pages where this is part of the recommended solution:

Compatible products

i-Cons

Smart Peltier sample conditioner with diagnostics, auto blowback and Modbus, in a compact 19 inch cabinet.

View i-Cons

SGI-300 / SGI-320

Peltier sample cooler with integrated pump, filter and condensate detector; SGI-320 for emission monitoring.

View SGI-300 / SGI-320

SP and SRP sample probes

Heated and non-heated probes with blowback, and retractable probes, in SS316, Inconel or ceramic.

View SP and SRP sample probes

Headline filters

Particulate, coalescing and PTFE membrane filters from Headline Filters, UK, for analyser protection.

View Headline filters

ACCURRA-TCD

Thermal conductivity analyser for binary mixtures of H2, He, Ar, N2 and others, with no reference gas.

View ACCURRA-TCD

Frequently asked questions

Which gases can ACCURRA-S measure?

Oxygen, carbon monoxide, carbon dioxide, methane and moisture or dew point, in ranges from ppm to 100 percent depending on the sensor model.

Can one analyser measure two gases?

Yes. The dual-channel version houses two sensors with common pneumatics and independent outputs. See the dual-gas analyser page for the combinations.

What must the sample be like?

Non-corrosive, non-toxic, non-flammable, dry and free of oil, at 2 to 10 psig and about 1 LPM.

Is ACCURRA-S suitable for hazardous areas?

No. It is a safe-area analyser. ACCURRA-Hz is the hazardous-area version.

How does it connect to my control system?

Through an isolated 4-20 mA output with dual range, failsafe relays and Modbus RTU over RS 485.

ACCURRA-S online gas analyser for O2, CO, CO2, CH4 and moisture