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Product Features
  • Handheld Odor meter is ideal for Before and After applications, such as air purification and cleaning service.
  • Real-time sampling mode displays odor change continuously
  • Memory sampling mode saves data based on the selected sampling rate. (up to 32732 data, 511 files)
  • Battery operated with 7 hrs continuous usage


  • Indicates the relative strength and odor classification numerically by comparing odor gas and purified air
  • DPS(Data Processing Software) allows the user to view data graphically while monitoring
  • Features an intake separate to the exhaust port to ensure accurate reading
  • OMX-SRM measures and finds odor source at factories, incinerator plants, or effluent treatment facilities etc
  • OMX-ADM Evaluation for deodorizing at hospitals or nursing homes etc.
  • OMX-TDM TVOC measurement for monitoring IAQ condition
Measurement Specifications
Object Gas Ethanol, Acetone, Hydrogen, etc
Odor Strength Level 0.0 to 999
Classification Class 0 to 90
Object Gas Hydrogen Sulfide, Methyl Mercaptan, Ammonia, etc
Odor Strength Level 0 to 999
Classification Odor Intensity 2.5 to 5.0
Object Gas TVOC (Toluene), etc
Odor Strength Level 0.0 to 9999 (µg/m3)
Classification n/a
General Specifications
Detection Method Two Semiconductor Gas Sensors
Sampling Method Continuous Sampling with Built-in Air Pump
Power Supply 4 x AA batteries or AC adaptor
Memory Capacity Up to 32732 data
Storage Temperature 0 to 40 ºC (32 to 104 ºF) with no condensation
Operating Temperature ‘-10 to 50 ºC (14 to 122 ºF) with no condensation
Dimensions W 74 x L 167.5 x H 35 mm
Weight 0.5 lbs 250g
Warranty 1 year
What’s included Meter, Suction nozzle, AC adapter, AA batteries, USB cable, Air purifying unit, Activated carbon (50cc/bag), Replacement filter for air purifying unit, Replacement filter for suction nozzle, Operation manual

There is no correlation between the indicated value of OMX-SRM and value of human sense of odor intensity, odor concentration or other odor index. OMX-SRM indicates relative value by comparing odor gas to purified air. This measurement is based on our original methodology. “Smell” is the information by human sense (sensitivity value), and there is no method that can accurately quantify various kinds of smells. There are some expressions such as “odor intensity” and “odor concentration” which are quantified based on human sense of smell. The OMX-SRM focuses on chemical substances contained in a smell and this device shows the relative strength of a smell numerically by using semiconductor gas sensors. The reading shown on display is calculated from the output from gas sensors using our original measurement to generate a numerical coefficient.

It is impossible to answer the first question from the perspective of the various points when measuring a compound smell. Even if device displays 300, you may perceive it as “an intense smell” or as “a week smell” depending on the kind of smell.

Smell has the following characteristics;/p>

1. Smell is a gas consisting of multiple ingredients.​

2. Smell has distinctive characteristics and there is no correlation with substance concentration and sensitivity value.

3. Also, they often impact to one another.​

4. The human sense has a relation of being proportional to the logarithm of substance concentration.

Since semiconductor gas sensors react with substance concentration, it is difficult to acquire correlation with the reading from this device and sensitivity value according to the reason of above (2). For example, see the table below, it is considered that we feel smell of toluene faintly when it is 5ppm although we feel Isovaleric acid faintly when it is 0.00004ppm. Like these two substances, there is a significant difference between the kinds of substances and, therefore, it is impossible to get correlation between sensitivity value and substance concentration.

Slightly recognize there is odor Slightly recognize the odor type Detect odor easily Strong odor Very strong odor
Methylmercaptane 0.0001ppm 0.0007ppm 0.004ppm 0.03ppm 0.02ppm
Hydrogen sulfide 0.0005ppm 0.006ppm 0.06ppm 0.7ppm 8ppm
Trimethylamine 0.0001ppm 0.001ppm 0.02ppm 0.2ppm 3ppm
Acetaldehyde 0.002ppm 0.01ppm 0.1ppm 1ppm 10ppm
Isobutanol 0.01ppm 0.2ppm 4ppm 70ppm 1000ppm
Xylene 0.1ppm 0.5ppmppm 2ppm 10ppm 50ppm
Butyric acid 0.00007ppm 0.0004ppm 0.002ppm 0.02ppm 0.09ppm
Toluene 0.9ppm 5ppm 30ppm 100ppm 700ppm
Valeric acid 0.00005ppm 0.0004ppm 0.004ppm 0.03ppm 0.3ppm
It is a reference value for discrimination of different smells by using two gas sensors.​ Below table is sample value of each odor. This value indicates classification for single component of odor (gas). If figure is greater, it doesn’t mean that odor is stronger.

When material strength is… Slightly recognize the odor type
O-xylene Around 5.7ppm Between 8 and 29
Acetone Around 110ppm Between 30 and 54
Valeric acid Around 0.25ppm Between 22 and 58
Butyric acid Around 0.27ppm Between 36 and 60
Propionic acid Around 0.97ppm Between 35 and 60
Isovaleraldehyde Around 0.18ppm Between 35 and 63
Ethanol Around 100ppm Between 41 and 67
Acetaldehyde Around 0.46ppm Between 36 and 69
Hydrogen sulfide Around 0.21ppm Between 36 and 78
Methylmercaptane Around 0.16ppm Between 41 and 77
Valeraldehyde Around 0.62ppm Between 41 and 66

* Above value is included a wide margin of error. It will be indicated narrower value range in actual measurement.

Please understand the main function of this device is that the relative strength of a smell can be shown numerically. This device can also provide you “Odor Classification” as second function and reference for discrimination of a smell by using two gas sensors the principle is uses the output value from two gas sensors that have distinctive characteristics and provide different output values.

When outputs from Sensor A and Sensor B are applied to vertical and a horizontal axis, figure shows degree of the “angle” between the peak of each output and the starting point. When you measure a pure single substance with this device in a chamber and get reading for each substance, you can make your own table, which is correlation table of a substance name and the discrimination reference value.

In case of compound smell, you cannot use the above-mentioned correlation table, for example when you find similar reading of hydrogen sulfide, you cannot consider that it is compound smell and main component is hydrogen sulfide. You cannot disregard chemical reaction of combined components and cannot consider it is compound smell of hydrogen sulfide mainly.

When measuring the effect of deodorization, or judging when a certain smell is removed, the discrimination reference value can be observed before deodorization. You will find intensity has fallen after deodorization, but discrimination reference value would be the same. If you deodorize by the adsorbing methods such as activated carbon, you can explain that the strength level is reduced without an unpleasant smell ingredient’s adsorbing uniformly and composition hardly changing.

There is a technique of masking which deodorizes with alcohol or fragrance. In this case, the perceived smell level falls dramatically but this is just, as you know, masking over the smell. Since this device also reacts to alcohol and fragrance, the intensity of the reading is possibly increased.

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