Does this detect levels of h2s outdoors? looking to measure levels of h2s in the air.

Yes, it detects H2S in the air. However, usually, outdoor H2S is much less than 1ppm, so this may not detect H2S. For example, the human nose can detect down to 0.0001ppm H2S.

it says it detects combustibles LEL. does that mean all combustibles. natural gas, methane, propane, acetelene, etc.

It checks gases that can mix with air and be explosive at the lower level. It will not tell you the kind or level of gas. Not sure if it will check every gas. Below is further explanation and a list of gases. Lower and Upper Explosive Limits for Flammable Gases and Vapors Before a fire or explosion can occur, three conditions must be met simultaneously. A fuel (ie. combustible gas) and oxygen (air) must exist in certain proportions, along with an ignition source, such as a spark or flame. The ratio of fuel and oxygen that is required varies with each combustible gas or vapor. The minimum concentration of a particular combustible gas or vapor necessary to support its combustion in air is defined as the Lower Explosive Limit (LEL) for that gas. Below this level, the mixture is too "lean" to burn. The maximum concentration of a gas or vapor that will burn in air is defined as the Upper Explosive Limit (UEL). Above this level, the mixture is too "rich" to burn. The range between the LEL and UEL is known as the flammable range for that gas or vapor. Methane - LEL.. 5% by volume in Air / UEL.. 17% by volume in Air Visual example to show where on the scale % of LEL is measured Visual example to show where on the scale % of LEL is measured Lower and Upper Explosive Limits The values shown in the table below are valid only for the conditions under which they were determined (usually room temperature and atmospheric pressure using a 2 inch tube with spark ignition). The flammability range of most materials expands as temperature, pressure and container diameter increase. All concentrations in percent by volume. Gas LEL UEL Acetone 2.6 13 Acetylene 2.5 100 Acrylonitrile 3 17 Allene 1.5 11.5 Ammonia 15 28 Benzene 1.3 7.9 1.3 Butadiene 2 12 Butane 1.8 8.4 n Butanol 1.7 12 1 Butene 1.6 10 Cis 2 Butene 1.7 9.7 Trans 2 Butene 1.7 9.7 Butyl Acetate 1.4 8 Carbon Monoxide 12.5 74 Carbonyl Sulfide 12 29 Chlorotrifluoro ethylene 8.4 38.7 Cumene 0.9 6.5 Cyanogen 6.6 32 Cyclohexane 1.3 7.8 Cyclopropane 2.4 10.4 Deuterium 4.9 75 Diborane 0.8 88 Dichlorosilane 4.1 98.8 Diethylbenzene 0.8 1.1 Difluoro 1 Chloroethane 9 14.8 1.1 Difluoroethane 5.1 17.1 1.1 Difluoro ethylene 5.5 21.3 Dimethylamine 2.8 14.4 Dimethyl Ether 3.4 27 2.2 Dimethyl propane 1.4 7.5 Ethane 3 12.4 Ethanol 3.3 19 Ethyl Acetate 2.2 11 Ethyl Benzene 1 6.7 Ethyl Chloride 3.8 15.4 Ethylene 2.7 36 Ethylene Oxide 3.6 100 Gasoline 1.2 7.1 Heptane 1.1 6.7 Hexane 1.2 7.4 Hydrogen 4 75 Hydrogen Cyanide 5.6 40 Hydrogen Sulfide 4 44 Isobutane 1.8 8.4 Isobutylene 1.8 9.6 Isopropanol 2.2 Methane 5 17 Methanol 6.7 36 Methylac etylene 1.7 11.7 Methyl Bromide 10 15 3 Methyl 1 Butene 1.5 9.1 Methyl Cellosolve 2.5 20 Methyl Chloride 7 17.4 Methyl Ethyl Ketone 1.9 10 Methyl Mercaptan 3.9 21.8 Methyl Vinyl Ether 2.6 39 Monoethy lamine 3.5 14 Monomethy lamine 4.9 20.7 Nickel Carbonyl 2 Pentane 1.4 7.8 Picoline 1.4 Propane 2.1 9.5 Propylene 2.4 11 Propylene Oxide 2.8 37 Styrene 1.1 Tetrafluoro ethylene 4 43 Tetrahydrofuran 2 Toluene 1.2 7.1 Trichloro ethylene 12 40 Trimethylamine 2 12 Turpentine 0.7 Vinyl Acetate 2.6 Vinyl Bromide 9 14 Vinyl Chloride 4 22 Vinyl Fluoride 2.6 21.7 Xylene 1.1 6.6

Can I put the probe in a furnace exhaust vent

Do not do that please. We have nearly the same product with correct filters and setup to do this. It is our COMBUSTION ANALYZER and actually cheaper than this version, look up ASIN B07QNFZ3X8 and B07Q3TBX1P, Thank you.

Brand	FORENSICS DETECTORS FD
Style	simple
Power Source	Battery Powered
Color	Yellow, Black
Product Dimensions	1.18"D x 2.56"W x 8.86"H
Item Weight	1.5 Pounds
Alarm	Vibration, Audible, Visual
Operating Humidity	95 percent
Sensor Type	Electrochemical
Manufacturer	FORENSICS
Part Number	70-04BB-GH7G
Item Weight	1.5 pounds
Item model number	70-04BB-GH7G
Batteries	2 Lithium Ion batteries required. (included)
Is Discontinued By Manufacturer	No
Wattage	10 Milliwatts
Batteries Included?	Yes
Batteries Required?	Yes
Battery Cell Type	Lithium Ion
Average Battery Life	10 Hours

4 Gas Monitor + Pump by Forensics Detectors | USA NIST Calibration Certificate | USB Recharge | 4 Gas with Probe for Confined Space |

Details

Description

Specifications

Have a Question? See What Others Asked

Common Questions