Glossary of Terms: G

Gage pressure
Pressure measured with respect to atmospheric pressure.
Gas analyzer
Equipment used to measure extremely small concentrations of gas (low or sub ppm) or one specific gas in the presence of several others.
Gas detector
Refers to equipment used in applications where there is normally no toxic or explosive gas risk and therefore is used to signal the presence of gas in otherwise safe conditions.
Gas monitor
Equipment used in applications where a gas or gas mixture is constantly present and is therefore used to signal a change in the concentration or mixture of the gas.
Gas
A state of matter in which the material has very low density and viscosity; can expand and contract greatly in response to changes in temperature and pressure; easily diffuses into other gases; readily and uniformly distributes itself throughout any container. A gas can be changed to the liquid or solid state only by the combined effect of increased pressure and decreased temperature. Examples include sulfur dioxide, ozone, and carbon monoxide.
Glare
Bright light that interferes with a person’s ability to see. Glare causes discomfort and can lead to eyestrain and headaches.
Gram (g)
A metric unit of weight. One ounce equals 28.4 grams.
Grounding
Electrical connection of one or more conductive objects to the earth through the use of metal grounding rods or other devices.