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Portable Gas Detectors

FI-8000 Optical Interferometer

Optical Interferometer - for Measuring Gas Purity in Air / O2 / N2 and CO2

The FI-8000 is the latest model from Riken in a long line of optical interferometers dating back to the 1930’s when Riken’s founder first developed the technology for Methane detection to help prevent explosion accidents on oil tankers and in coal mines.

FI-8000 gives extremely accurate (typically 3% of Reading across the whole range) and stable readings as long as there is minimal or no interference gases present. See below Downloads and Datasheet for some examples of the versions available. If you don't see the gas combination required, please Contact us

Note: you can have up to 8 different gases and ranges in one instrument as long as they are all in the same chamber length see data sheet gas list.

Product Features

In the 1970’s Weatherall developed with Riken the instrument for anaesthetic gases. In conjunction with Dr John F Nunn’s research, published in the British Journal of Anaesthesia, helped validate the principle of interference refractometry as a technique suitable for measuring anaesthetic gases such as Halothane, Isoflurane, Sevoflurane, Desflurane and Enflurane.

The History of Riken Interferometers

Today, Riken’s interferometer is considered the instrument of choice for anaesthetic vaporiser checking, in part due to its portability, robustness, low cost, and reliable measurements. It is used throughout the NHS, veterinary clinics MOD, and by vaporiser manufactures / service companies.

The FI-8000 is also used in many other applications; such as Fumigation, Solvents, Inert Gases, Toxic Gases, and Gas Purity.


Model FI-8000
Measuring principle Optical Interferometric Method
Measuring gas (other gases may be possible. Please contact us if you would like to measure a non-listed gas)
Indication accuracy Within ±3% (at constant temperature)*
Type TYPE P-_ _-_ _ TYPE A-_ _-_ _
Sampling method Pump suction type Hand-aspirating type
Self-diagnosis function Low battery, Low light , Low contrast, abnormal atmospheric pressure and abnormal temperature
Display LCD digital (7-segment value display + code + 20 segment word x 2 lines)
Screen Measuring gas, gas concentration , measuring unit and battery capacity reminder
Power source Alkaline battery pack(AA size battery x 3 pcs) (standard)
Or, Lithium ion battery (optional)
Ingress proof rating IP67 equivalent
Ambient humidity & temp Temperature : -20~50°C, Humidity : Below 95%RH (non-condensing)
Dimensions Approx. 154(W)×127(H)×81(D)mm
Weight Approx. 1.1kg (including alkaline batteries)
Approx. 1.2kg (including lithium ion batteries)
Explosion proof Intrinsically safe(Exia II CT4) (ATEX)
Continuous operation Over 12 hrs (for alkaline battery use)
Over 18 hrs (for lithium ion battery use)
(25°C with no backlight on)
Over 16 hrs (for alkaline battery use)
Over 24 hrs (for lithium ion battery use)
(25°C with no backlight on)
External output IrDA (for data logging)
Function Data logging , atmospheric pressure correction, temp. compensation

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