Personal monitors calibration

Section 1 of the Report presents the quantities Hz and E and the relationship of each quantity to its corresponding radiation protection system. Section 2 describes the use of personal monitors for workers in the United States, including their calibration and how they are worn on individuals in various occupational settings. Section 3 discusses practical ways to use one or two personal monitors to obtain estimates of Hz and E. Section 4 provides the NCRP s... 

The calibration procedure provides a body of data about how the personal monitor responds to the various irradiation conditions. These data are converted into formulas or algorithms that generate a value for Hp(lO) for the irradiation conditions assumed in the workplace. The formulas or algorithms apply to the personal monitor system calibrated, and do not change unless there is a modification in the design or types of radiation detectors used in the personal monitor. An example of such a body of data for a particular monitoring device is provided by Ehrlich and Soodprasert (1994). 

Complete calibration of the personal monitors using the NIST secondary standards for all irradiation conditions is not done routinely. More often, the physical response of the components of the personal monitor is compared to the response of other calibrated radiation detection instruments to assess whether the personal monitor components respond the same as during complete calibration. This comparative calibration usually involves fewer radiation fields. 

The response of a personal monitor varies when worn on individuals of different sizes and shapes and when worn at different locations on the body (Jahr et al., 1989 Wagner, 1989). Personal monitors showing good agreement when irradiated on a specific backscatter medium under calibration conditions might disagree when irradiated on another type of backscatter medium or on the body of an individual (Alberts et al., 1989). 

The values of He (estimate) are obtained from values of Hp(lO) consistent with the calibration procedures for personal monitors used in the United States (i.e., a 30 X 30 X 15 cm PMMA slab), and... 

In order to get instantaneous results, continuous filter tape instruments have been developed based on modification of the colorimetric Marcali method. The instruments have been used for continuous air monitoring of production sites and for personal monitoring of isocyanates. A limitation with the filter tape instruments is that no compound-specific information is given in means of retention times or detector specific structural information. Since the instruments have to be calibrated for the different isocyanates, quantitative estimation of mixed isocyanate exposures is troublesome. Problems associated with influence of interfering compounds, humidity, and collection of particles have been reported. " ... 

See also Air Analysis Outdoor Air. Atomic Absorption Spectrometry Principles and Instrumentation. Atomic Emission Spectrometry Principles and Instrumentation. Environmental Analysis. Gas Chromatography Overview Principles Instrumentation. Liquid Chromatography Overview Principles Instrumentation. Personal Monitoring Active Passive. Quality Assurance Quality Control Instrument Calibration. Spectrophotometry Ovenriew Inorganic Compounds Organic Compounds. 

Implementation includes evaluation of work areas for environmental hazards. It may involve collecting and evaluating data from personal monitoring devices. It may cover testing and calibration of instramentation and monitoring systems. 

Facilities and services for radiation protection and safety must be well established at the national level. These include laboratories for personal dosimetry and environmental monitoring, and calibration and intercomparison of radiation measuring equipment they could also include central registries for radiation dose records and information on equipment reliability. 

The performance of a diagnostic X-ray machine should be checked at least annually with appropriate instruments by a qualified person. If the capability to do this is not available in-house, a qualified consultant should be hired to do the task. If any maintenance is done or if the machine is relocated, a survey should be undertaken for leakage radiation fromthe source. If the unit is moved to another facility, the exposure levels in the adjacent areas should be tested to ensure that the exposure levels are within the permissible limits forcontrolled and uncontrolled areas. Records of all maintenance, surveys, leakage checks, calibration, personnel monitoring, etc. should be maintained at the facility and at the radiation safety office. Because of the long latency period for cancer developing from radiation exposures, it would not be unreasonable to maintain personnel exposure records for up to 40 years. 

The new Sierra Monitor Model 5100-25-IT Ammonia Gas Sensor Module utilizes smart sensor teehnology. This network-enabled gas deteetor includes extended ealibration frequeneies only requiring calibration every six months non-intrusive, one-person ealibration and user-friendly, eight-eharaeter, fixed and SCTolhng LED display. Sierra Monitor Corp., wwwsierramonitor.com, (800) 727-4377. Cede 283... 

Such a filtration probe has been tested with very good results in a number of analyses with a special enzyme thermistor version designed for use in industrial environments. Figure 2 is a schematic illustration of an enzyme thermistor arranged for process monitoring by repeated flow injection analysis. The interval between sample injections is chosen with respect to how fast the analyte concentration changes. A typical figure is four to five sample injections per hour. The injection valve and a sample selector valve for selection of different samples or calibration solutions and the pumps are controlled with a personal computer with a 386 processor, which also... 

Laboratory measurements use special instmments for highly accurate analysis and field instmments are used for a quick assessment of conditions. Some instmments are attached to workers (personal samplers or dosimeters) to monitor exposures. Some of these dosimeters determine directly if an exposure exceeds the 8-hr TWA. Arrays of sensors, analysis equipment, and alarm systems are managed by computers to provide continuous monitoring for releases. They warn people by triggering evacuation or corrective procedures for equipment. Many of the instmments require regularly scheduled calibration to assure accurate results. There are a wide range of collection procedures and devices. This discussion is a limited review of collection and analysis equipment. 

For biological monitoring of persons occupationally exposed to nickel, where higher concentrations might be expected, an extraction ratio of 4 1 is proposed. For calibration the aqueous nickel standards should be treated as the urine samples. The operational A AS parameters and the reliability criteria for the nickel determination in urine are presented in Table 2. 

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