Forensics Oxygen Analyzer Review: Analyse Every Fill Yourself

A 0.1 percent resolution electrochemical analyser, and the rule that you verify your own gas.

Specifications

Specifications above come from Forensics Detectors' published specifications. Treat pricing as approximate, since Amazon pricing moves.

What it does well

• Owning your own analyser means you can verify a fill anywhere, including at operations that hand you a cylinder and a sticker rather than an analyser.
• A 0.1 percent resolution with error under 0.2 percent is more than adequate for recreational nitrox, where the difference between a 32 and a 36 percent mix changes your maximum operating depth materially.
• A three-year sensor with a stated life means you know when to replace it rather than wondering whether readings have drifted.
• A swivel T-piece makes taking a reading from an awkwardly positioned valve a one-person job.
• The water-resistant case matters because this lives in a dive bag, and dive bags are wet.

Where it falls short

• Electrochemical sensors are consumable. They age, they drift, and they need replacing. A sensor past its life gives readings that look normal and are wrong, which is the worst failure mode an instrument can have.
• It must be calibrated before use, normally against air at 20.9 percent, and a reading taken without calibrating is not a measurement.
• Readings are affected by temperature, humidity and pressure, so flow the gas slowly and let the reading settle rather than taking the first number that appears.
• It reads oxygen only. It tells you nothing about carbon monoxide, moisture or contaminants, which are a real concern with a poorly maintained compressor.
• Owning an analyser does not make you qualified to dive nitrox. That requires a nitrox certification, and the training covers the maximum operating depth and oxygen exposure calculations that the analyser number feeds into.

What owners report

Owner reports on this analyser are positive on accuracy and on build for the price, with the usual notes about sensor life and about calibrating in clean air away from a running compressor. Divers who own one describe the main benefit as independence: not having to queue for a shop analyser or take a fill on trust.

The practice matters more than the product. Analyse the gas yourself, record what you measured, set your computer to that number rather than to what the label says, and calculate your maximum operating depth. Our MOD calculator and the MOD chart do the arithmetic, and our partial pressure chart shows why the depth limit tightens as the mix gets richer.

Whether to dive nitrox at all is covered in our nitrox versus air comparison, which is honest about the fact that nitrox extends no-decompression time and does not reduce narcosis and does not let you dive deeper. Our nitrox guide covers the rest. Nitrox diving requires nitrox training. Nothing on this page replaces training. Dive equipment is only as safe as the diver using it, and every item here assumes you hold a current certification appropriate to the diving you are doing.

Who it suits

• Divers who use nitrox regularly and want to verify their own gas.
• Anyone diving at operations that do not provide an analyser at the fill station.
• Divers travelling to places where fill quality and labelling vary.

Who should skip it

• Divers who only breathe air, where the analyser has no role.
• Anyone without a nitrox certification, who needs the training before the instrument.
• Occasional nitrox divers whose local shop provides a calibrated analyser at the fill station.

Alternatives worth considering

Keep reading

• Nitrox vs air
• Nitrox MOD calculator
• Equivalent air depth calculator
• Nitrox MOD chart
• Partial pressure chart
• Nitrox diving guide
• Suunto Zoop Novo review
• Best dive computers

This review draws on published specifications, manufacturer figures and the consensus of verified owner reviews. We have not tested this product ourselves, and we say so rather than implying otherwise. As an Amazon Associate we earn from qualifying purchases.