Glossary of Terms

Instrumentation for Emergency, Investigatory, and Remedial Response

Instruments are equipped with audio, visual and or vibrating alarms that may be set at threshold limits for gas or conditions of concern.

AAA, AA, C, D size and 9 volt snap on. These batteries are generally single use/disposable. Rechargeable alkaline batteries are available but seldom used. Interchangeable with lithium and nickel rechargeable batteries.

Power generated for plug-in to utility supplied systems.

External handheld pump (bulb) with tubing.

Use of electromagnetic radiation absorbed and emitted by atoms. Used in mercury vapor detection.

Test/Auto-calibration checks Fresh air/zero calibration. Use of manufacturers supplied known gas exposure for appropriate readings. Stand Alone Docking Stations. Available to cradle calibration gas and expedite the process/provide additional data storage capabilities. Full Calibration Outsourced to manufacture/representative or performed in-house by trained technicians to certify calibration of meter accuracy.

Catalytic bead sensors are used primarily for the detection of combustible gases Based on the premises that all electrically conducted materials change their conductivity as temperature changes. There is a coefficient of temperature resistance (ct) for each combustible gas mixture.

Manufactured as weapons to be used in warfare and must be toxic enough to cause instant harm when inhaled or in contact with skin.

Turn on/off, gas readings, battery condition, and calibration data. Software is available for transfer of information to a PC for data storage and remote monitoring.

Passive monitoring installed in a port on the meter.

(DC Power) can be used to recharge batteries and may be plugged into vehicle ‘cigarette lighters’ for long-term monitoring.

Measures the concentration of a target gas by oxidizing or reducing the gas at an electrode and measuring the resultant current commonly used for CO and H2S.

For combustible gases use of an oxidizing agent such as platinum or palladium combustible gas meters measure flammable gas concentration as a percentage of the LEL of the calibrated gas.

Using spectrometry for the measurement of hundreds of different compounds, the field gas analyzer can be used as a survey tool, specific gas monitor or for Chemical Warfare Agents (CWCs). This is not a monitor to be used for confined space entry. Software allows the use of a library of compounds that can be identified in the field. Gases are drawn into a portable monitor for spectral analysis; with information then transferred to a PC for data retrieval, further analysis and record keeping. Both identification of a specific gas and concentration can be obtained.

A measurement technique for recording infrared spectra. (FTIR) Spectroscopy

Useful for measuring a broad range of inorganic and organic chemicals in the air IR analyzers operate by passing Infrared radiation generated from a heated metal source through a gas sample. The IR radiation is absorbed by the chemical in the sample. The IR analyzer is preloaded with a library of known chemicals for identification and concentration of chemicals in the air. It measures a variety of gases to include CO2, CO, CH4, NO and SO2.

Chemicals will absorb infrared light. The absorption pattern is unique to specific chemicals which is called a spectrum. The infrared spectrum is recorded by passing an infrared beam through a sample and light energy absorbed reveals specificities at each frequency or wavelength. The spectrum of the sample can be matched to a library sample for identification and quantification of a chemical.

Use analytical technique to identify ionized molecules in gas phase. Use for mercury vapor detection.


Liquid Crystal Display


Liquid Emitting Diode

Single gas calibrations are established in a standard library and through the use of a PC matched for selection of a compound from the infrared spectrum.

(Li-Ion) most commonly used rechargeable battery.

Using spectrometry for the identification of unknown materials (solids/liquids). Software allows the use of a library of compounds that can be identified in the field. Solid and liquid chemical samples are placed on a portable monitor for spectral analysis; with information then transferred to a PC for data retrieval, further analysis and record keeping.

(NiCD) Small rechargeable battery.

(NiMH) Rechargeable battery, common use for AA penlight size.

Based on electrochemical (galvanic) cells. The generated current in the sensor, which is produced from an oxidation reaction, is directly proportional to the rate of oxygen diffusion into the cell. Meters are generally calibrated oxygen concentrations between 0 -25%. Normal oxygen is 20.9%. Meter alarms are set at concentrations lower than 19.5% or above 23.5%.

Use of a high energy ultraviolet (UV) light source to ionize chemicals in an airstream, The charged molecules are collected on a charged surface, which generates a current that is directly proportional to the concentration of the chemical in the air being sampled for the measurement of volatile organic compounds and other gases. PIDs are broadband detectors with a sensitivity that differs for each VOC.

An analytical technique using laser technology.

Short Term: X Exposure Limit value above which exposure to a chemical substance should not occur. Usually relates to a 15 minute reference period. Time Weighted Average: The exposure to a chemical can be used when both the chemical concentration and time for exposure varies over time. It is used as the average exposure to a contaminant to which workers may be exposed without adverse effect over a period such as an 8 hour day or 40 hour week.

Gas detectors that measure the concentration by oxidizing the target gas at an electrode and measuring the resulting current. Also known as an electrochemical gas sensor.

Use of electrochemical technology (NH3, HCN, PH3, SO2.)

NATO's International Task Force established a list of 25 Toxic Industrial Chemicals (TIC's) that could cause harm in military operations. The TICs are considered easier to use than conventional chemical and biological weapons and are more readily available.