Lifeloc «Sequence» software ensures each step of the testing process can be tailored to your specific test protocol and user situation. Where multiple chemicals may be present in the environment, interference can be a problem. A unique absorbance wavelength must be identified to distinguish one chemical from another. Then the female driver, who was an experienced drunk, stated she would not take any tests because she had not been drinking.
The process works by using photocells to analyze the color change of a redox (oxidation-reduction) reaction. A breath sample is bubbled through an aqueous solution of sulfuric acid, potassium dichromate, and silver nitrate. Exercise caution in cleaning the lamp window, as these are fragile. This disc is placed in the seat between the operator and the machinery. The fatigue-decreased proficiency boundary is a limit for time-dependent effects that impair performance. Non-regulated testing practices are determined by company policy, local state laws and trade union agreements.
There are some tubes, such as those for blister and nerve agents, which give a qualitative detection of the presence of that family of chemicals up to near IDLH levels. The HHA units are small, the test can be performed in the field, and they rely on a visual colorimetric change for sample results. All battery types will self-discharge to some degree during periods of prolonged storage. Exceeding these exposure limits makes it difficult for passengers to eat, read or write when traveling.