RASI 700 ENG - Engine Exhaust Emissions Tester

The most trusted analyser for Service and Commissioning Engineers working on Nat Gas, Landfill, Biogas and Diesel Industrial Engines

  • Long Life O2 sensor with up to 5 years expected life
  • Separate NO and NO2 cells for true and correct NOx measurement as required by the Environmental Agency
  • 20000 ppm CO sensors
  • CO sensor fresh air valve for working with high CO concentration
  • Display measurement values in ppm and/or mg/m3 with O2 reference (user selectable)
  • Continuous back pressure measurement along with combustion analysis
  • Blue-tooth® as standard for communication with mobile app
  • Works with both IOS and ANDROID devices
  • Special Engine sampling probe with Viton line for NO/SO2 measurement optimization


The RASI 700 is currently one of the most used emissions gas analyser (NOx meter) in the UK for servicing, commissioning and testing any type of industrial engines such as, natural gas, landfill, biogas, propane and Diesel engines.
The RASI 700 is light, extremely portable and easy to use with long lasting batteries. Batteries are charged trough MINI USB port. It comes with pre configured specific measurement menus which help the operator to make the right selection depending from the application. It avoid the need to keep changing the configuration of the display depending from the measurement task that an engineer need to carry out.
The Basic Kit is equipped with O2, CO(H2)0-20000 ppm, NO and NO2 measurement cells. The more advanced kits can be equipped with NDIR CH4%, CO2% and H2S (EC) to measure the quality of the fuel Gas. These KITs are particularly suitable for commissioning engineers working on BIOGAS or LANDFILL Gas Engines who require to know the CH4% content during the commissioning phase.
All the RASI700’s measures exhaust gas temperature, back pressure and provide Lamba ( Air Ratio) readings.
Each RASI700 is equipped as standard with Bluetooth communication to work together with our MRU4U mobile app or WIN4U Windows software.

True NOx measurement

The continuous & high fluctuation of the NO2 portion in the engine exhaust requires to make separate measurement of both NO and NO2 to provide accurate “True” NOx values of the engine. Equally important is ensure that the Total NOx is reported in the correct way.
The Environmental Agency requires the operator to report the total NOx in mg/m3, in term of NO2 and corrected for O2% reference.

Free mobile app ( IOS/ANDROID) for remote control, Fisualization & reporting

Work faster and safer with our new MRU4U mobile app with specific engine reporting function. Capture and share data with your colleague in a more efficient way. Turn your smart device into a gas analyser. Leave the analyser in the exhaust and be in front of the screen “ Noxing” and “mapping” the engine. Data are saved under a Job Number and additional information such as Delivery Pressure, Engine Load, CH4% content and Engine condition can be entered to be saved together with the exhaust measurements.

Measurement made easy

The RASI700 smart menu guides step by step trough the whole measurement process to make it easy and safe for the operator. The large 3.5 “ TFT graphic colour display provides information relevant to the application and guides the user through the measurements from start to finish. No instrument-specific knowledge is therefore required. Instrument settings, such as correct O2% reference and display values are activated by selecting the application. User can re-name programme and change setting as required.

Higher CO cell 0-20000 ppm and sensor protection by additional purge pump

All the RASI 700 are now equipped as standard with an higher range CO (H2 comp) measurement cell which is able to with-stand CO concentration up to 20000 ppm with-out any dilution. The new cell also have an enhanced NO filter. In addition to this each RASI700 is equipped as standard with a CO purge pump which will protect the cell and prevent saturation from unexpected high CO level.

Special Engine Gas Sampling probe

Each RASI 700 is supplied with a sampling probe which is especially designed for optimal use on engines exhaust measurements. The probe is supplied with a replaceable tip , 365 mm made in stainless Steel with an operating temperature up to 850 °C and 2.7 m Viton sampling line to prevent NO2 abortion. Thanks to the COAX design, integrated type K thermocouple and triple hose, the RASI 700 provides gas,  temperature and back pressure measurement at the same time


O2 measurement 
Range 0 to 25 %
Accuracy ± 0.2 % Vol
Resolution ± 0.1 % Vol
CO measurement with H2 Compensation
Range 0 to 20000 ppm
Accuracy ± 10 ppm or ± 5 % of reading up to 4000 ppm
± 10% of reading from 1000 to 20000 ppm
Resolution 1 ppm
Low CO measurement with H2 Compensation
Range 0 to 300 ppm
Accuracy ± 2 ppm or ± 5 % of readings
Resolution 0.1 ppm
Hi CO measurement %
Range 0 to 10%
Accuracy ± 0.02% of rdg up to 4 % 
± 10% of rdg from 4 % to 10%
Resolution 0.01 %
NO measurement (option) 
Range 0 to 5000 ppm
Accuracy ± 5 ppm or ± 5 % of reading up to 1000 ppm
± 10% of reading from 1000 to 5000 ppm
Resolution 1 ppm
Low NO measurement (option) 
Range 0 to 500 ppm
Accuracy ± 2 ppm or ± 5 % of reading
Resolution 0.1 ppm
NO2 measurement (option) 
Range 0 to 1000 ppm
Accuracy ± 5 ppm or ± 5 % of reading up to 200 ppm
± 10% of reading from 200 to 1000 ppm
Resolution 1 ppm
Low NO2 measurement (option) 
Range 0 to 100 ppm
Accuracy ± 2 ppm or ± 5 % of reading
Resolution 0.1 ppm
SO2 measurement (option) 
Range 0 to 5000 ppm
Accuracy ± 10 ppm or ± 5 % of reading up to 2000 ppm
± 10% of reading from 2000 to 5000 ppm
Resolution 1 ppm
H2S measurement (option) 
Range 0 to 2500 ppm
Accuracy ± 5 ppm or ± 5 % of reading up to 50 ppm
± 10% of reading above
Resolution 1 ppm
CO2 NDIR measurement for emissions (option) 
Range 0 to 40%
Accuracy ±0.3 % of Volume  or ± 5 % of reading 
Resolution 0.01 %  
HC NDIR measurement for emissions (option) 
Range 0 to 40000 ppm
Accuracy  ± 400 ppm or 5% reading
Resolution 10 ppm  
CO2 % ( calculated from O2) when NDIR sensor not installed
Range 0 to CO2% Max
Accuracy ± 0.3 % Vol
Resolution 0.1 %
Flue gas temperature measurement 
Range – 50 to 1200 °C
Accuracy ± 2 °C
Resolution 0.1 °C
Air Temperature measurement 
Range – 50 to 100 °C
Accuracy ± 1 °C
Resolution 0.1 °C
Flue Gas Draught measurement 
Range ± 50 mbar
Accuracy ± 0.02 mbar
Resolution ± 0.001 mbar
Pressure measurement 
Range – 300 to 300 mbar
Accuracy ± 0.02 mbar
Resolution ± 0.001 mbar
CO/CO2 Ratio Calculation 
Range 0 to 99999
Resolution 0.0001
Efficiency (Net, gross, Condensing) calculations 
Range 0 to 120% ETA
Resolution 0.1 %
Air Ratio Calculation 
Range 1 to 9.99
Resolution 0.01
Excess Air Calculation 
Range 0 to 99.9 %
Resolution 0.1%
Heat losses Calculation 
Range 0 to 9.99 %
Resolution 0.1%
Flow Gas measurement (option) 
Range 3 to 100 m/sec
Accuracy ± 1 m/sec or ± 3% of reading
Resolution 0.1 m/sec
Conversions calculation 
emissions calculation ppm/o2% reference, mg/m3, mg/m3 with O2 reference, NOx mg/m3 in term of NO2
Pres-set fuels Nat Gas, Heavy Oil Light Oil, LPG, Propane, Butane, Kerosene,Coal, Diesel,Petrol,Coke, Anthracite, Wood@0%, Wood@10%, Wood@20%, Wood@30%, Wood@40%, Wood@50%, Pellets
Digital & Software
Communications mini USB, IRDA and Bluetooth as standard
Data logging 16000 Data log on internal memory  & SD card
Mobile APP ( Free) MRU4U working on IOS & Android
Software (Optional) MRU4WIN emissions software
Display 3.5″ TFT color display, 6 lines , graphic
Weight 750 g
Dimension 110 x 225 x 52 mm
IP protection IP 30
Power/main Li-Ion  internal rechargeable batteries, USB charger/lead supplied
Operating/Storage temperature 5 to 45 °C/ -20 to 50 °C
Warranty 2 years on instrument, 2 years on O2 sensor, 1 year on all other sensors
Approvals Independently tested to BS EN 50379-2

Scope of Supply

RASI 700 main Unit with integrated water trap and filter, temperature and pressure readings and IRDA communication for optional printer, Li-Ion , SD card and rechargeable batteries. Equipped with:
O2 Sensor LL 0-25 %
CO Sensor 0-20000 ppm
NO Sensor 0-5000 ppm
NO2 Sensor 0-1000 ppm
CO sensor Protection
AUX connection
Bluetooth communication ( IOS/ANDROID)
MRU4U  mobile app ( IOS/ANDROID)
MRU4WIN “light version ” for desk stop use
USB lead/wall charger
Gas Sampling probe for Industrial Engines,  with 2.7 m Viton line, 365 mm immersion probe, heat deflector and integrated Thermcouple
Calibration certificate
Double wall robust ABS transport case

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RASI 700 ENG – Engine Exhaust Emissions Tester