17. Personal Sampling

Question 1

Sampling Systems

Answer 1

2 Types
- 1 . Active Samplers that mechanically move contaminated air through a collection medium

• 2. Passive samplers rely on natural rather than mechanical forces to collect samples

Question 2

Active Samplers

Answer 2

General Considerations
Active sampling systems mechanically collect samples on or through a selected medium (id filtering or collection substance) THe medium is then analyzed in the laboratory to identify and quantify the collected contaminant(s).

Question 3

Sampling Pumps

Answer 3

Active sampoling systems typically rely on celectrcally powered pumps to mechanically produce air movement. The most practical electrical sampling pumps are powered by rechargeable batteries and can opeate continuously at constant flow rates for at least eight hours. Generally, they are compact portable, and quiet enough to be worn by individuals when monitoring personal exposures. The type of portable pump selected is generally determined by such factors as the physical properties of the contaminant, the collection medium, and the collection flow rates specified by the analytical method. A rugged design that is light weight and has battery capacity long enough for the assignment are qualities to look for when selecting a pump.

Question 4

Calibration

Answer 4

Atmospheric sampling systems must be accurately calibrated (ie adjusted) to a specific flow rate. Calibration ensures that the measurement data can be correctly interpreted. For example, it is important to calibrate the flow rate of an electrically powered pump. This ensures that a constant flow rate, which often is specified in standard analytical methods (such as EPA-specified analytical methods) can be achieved.

The pump should be calibrated while attached to the filter media before and agter each sample is collected and the two numbers documented on a calibration log sheet. The pre and post calibration values should then be averaged. The post calibration flow rate is typically less than the pre calibration flow rate due to the filter media pores becoming clogged withsample and decreasing the pumps efficiency. A decrease in battery charge may also slow the pump down over the course of a sampling run.

Passive sampling systems, however, because of their simplicity of design and operation, require no formal calibration. Natural air movement brings the contaminant to the sensor therefore n o pump is required.

At a minimum, an active sampling system should be calibrated both before and after a prescribed sampling period. The overall frequency of calibration depends upon the general handling oand use a sampling system receives. Pump mechanisms should be recalibrated after they have been repaired, when newly purchased, and following any suspected abuse.

Question 5

Passive samplers

Answer 5

The key advantage of passive samplers ( dosimeters) is their simplicity. These small, lightwight devices do not require a mechanical pump to move a contaminant through a collection medium. Thus, calibration and maintenance are reduced or eliminated, although the sampling period must still be accurately measured. Despite this obvious advantage, errors can occur in observer interpretations. Temperature and humidity can affect accuracy as well in both active and passive systems.

Question 6

Radiation Dosimeters

Answer 6

Radiation dosimeters measure personal dose exposures to radiation. These dosimeters are used on sites where radioactive materials are known to be present and careful monitoring of personnel is necessary. As there are different monitors for the different types of radiation, there are also different types of personal dosimeters for different types of radiation.

Question 7

Thermoluminescent Dosimeter

Answer 7

TLD badges provide a permanent record of an individual’s dose equivalent of beta, gamma, and X-ray radiation. THe albedo tld is a neutron dose detection device worn when working in or around a neutron radiation field. Such dosimeters must be sent to a laboratory for analysis.\

Question 8

Direct Reading Dosimeter

Answer 8

The more chirps it emits the stonger the exposure to tld. the chirpy. Pencil type devices

Question 9

THe digital dosimeter

Answer 9

Battery powered direct reading instrument with digital readout in mR. There is a devise called the chest thumper because it vibrates or thumps the chec=st of the wearer

Question 10

Personal sampling plan

Answer 10

a sampling plan can be difficult because of the following 3 items

1. it is difficult to decide what to sample
2. many workers move around the work area, some perform a variety of tasks and some stay in one specific area
3. efficiently keeping track of the sampling data records requires attention and organization

28 substances - sub part z
sets specific requirements for the monitoring of workers.
no

if it doesnt m=meet or reach the limits=s personnel monitoring is not required