Direct-Reading Monitoring Instruments

DOE-EM-STD-5503-94

the use, care, limitations, and operating characteristics of air monitoring instruments. These

individuals should also be responsible for the maintenance and calibration of all air monitoring

equipment.

Calibrations should be in accordance with methods indicated in NIOSH's Manual of Analytical

Methods (latest edition), EPA methods, and/or methods recommended by the equipment

manufacturer. Maintenance of instruments should be in accordance with methods recommended

by the equipment manufacturer or by the SSHO.

The EPA methods to be used for ambient air monitoring should be specified, as well as the use of

NIOSH methods for worker exposure monitoring/sampling. The use of analytical laboratories

accredited by EPA and/or the American Industrial Hygiene Association (AIHA), should be

specified. Samples collected using NIOSH methods should be analyzed only by laboratories

currently accredited by the AIHA. When radiological samples are to be analyzed, laboratories

with appropriate accreditation should be used.

The following sections discuss in more detail the detection principle, limitations, and features of

instruments which should be utilized during environmental restoration projects. For selection of

all instruments, a number of factors should be considered such as:

Accuracy,

Mobility,

Potential interferences on performance,

Alarms,

Remote sensing,

Battery life,

Calibration required,

Explosion proofing, and

Sampling range.

8.4.1. Direct-Reading Monitoring Instruments

Unlike time-integrated sampling devices, which are used to collect samples for subsequent

analysis in a laboratory, direct-reading instruments (the term direct-reading is used

synonymously for the term real-time) provide information at the time of sampling, thus enabling

rapid decision-making. Data obtained from direct-reading monitors can often be used to assure

proper selection of personnel protection equipment, engineering controls and work practices. The

instruments can often provide the trained and experienced user the capability to determine if site

personnel are potentially exposed to concentrations which exceed exposure limits or action levels

Direct-reading monitors can be useful in identifying oxygen deficient atmospheres, IDLH

conditions, toxic levels of airborne contaminants, flammable atmospheres, and radioactive

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