The lamp may need to be cleaned more frequently when used in a high temperature, high humidity environment. The chamber is deployed directly in the area to be measured. High concentrations of chlorinated hydrocarbons, such as trichloroethylene or acid gases such as sulfur dioxide, will depress the meter reading in the presence of a high concentration of combustible gas. Can the unit be used in a dusty environment without damaging it or requiring factory service? The response factor is the ratio of the detector response for a particular chemical relative to a reference gas, usually isobutylene. Periodic factory calibration or equivalent by a laboratory is essential.
Because the sensor must be swallowed, the CorTemp™ system is considered a medical device and must be used under the supervision of a physician. Both models have a zero air filter which removes mercury vapor, mercaptans, and hydrogen sulfide. Other groups, most notably aromatic rings and carboxylic acids can give similar absorbance readings. Interfering compounds Some natural and volatile interfering compounds do exist, however. Some weaknesses of PCR to consider are the following: potential interferences from other substances in the sample, reagent stability, and sample viability, because PCR will detect the presence of both live and dead organisms, but will not distinguish between the two. After prolonged operation or exposure to particulate-laden air, the interior walls and the two glass windows of the sensing chamber may become contaminated with particles. The drunkometer was manufactured and sold by Stephenson Corporation of Red Bank, New Jersey. In 1954 Robert Frank Borkenstein (1912–2002) was a captain with the Indiana State Police and later a professor at Indiana University Bloomington.
Some substances can act as interferences and produce false positives, such as insecticides, antifreeze, and petroleum products. A similar product, termed «3-way» paper is also available. One table is for longitudinal (foot to head; z axis) exposures, with the lowest exposure limit at 4 to 8 Hz based on human body sensitivity. Use only the type of battery specified on the safety approval label, and replace batteries in a nonhazardous area. II. Equipment Maintenance and Calibration Service intervals for equipment may be determined by checking the CTC webpage for Equipment Servicing Information. These instruments can typically be set to count a sample for a specified time. Retrieved 2012-11-19. ^ «Test a Tippler’s Breath». Popular Science.