Survey Meter Overview
Survey Meter testing and use
Environmental Health & Safety
Author
02/14/2020
Added
412
Plays
Description
Initial overview of normal testing and use of a survey meter used to detect radiation contamination.
Overview: Survey Meters to detect radioactive contamination
Searchable Transcript
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- [00:00:01.010](upbeat music)
- [00:00:12.800]A survey meter is a common instrument
- [00:00:14.870]using different radioisotopes.
- [00:00:17.240]Using different probes, a survey meter can detect alpha,
- [00:00:20.490]beta, and gamma emissions
- [00:00:22.090]from radioisotopes commonly used in research
- [00:00:24.810]such as phosphorus-32, sulfur-35, or iodine-125.
- [00:00:30.230]It cannot detect tritium or iron-59 very efficiently.
- [00:00:34.750]The survey meter instrument audio provides a brief click
- [00:00:37.610]for every radiation event detected.
- [00:00:39.578]This video is intended as an initial overview
- [00:00:42.760]of the normal testing and use of this meter.
- [00:00:45.712]Looking at the survey meter
- [00:00:47.700]you see the meter probe containing the detector,
- [00:00:50.236]the readout dial, the calibration sticker,
- [00:00:54.480]the audio switch and range selector switch.
- [00:00:58.070]Survey meters also have an attached check source.
- [00:01:02.000]The instrument dial shown has three arcs:
- [00:01:05.020]a counts per minute scale, a milliroentgens per hour scale,
- [00:01:09.700]and a milliroentgens per hour scale
- [00:01:11.840]for the times 100 scale only.
- [00:01:15.120]At UNL we only use the top counts-per-minute scale
- [00:01:18.350]which can be used for the times 0.1, times 1, times 10
- [00:01:23.550]and times 100 ranges.
- [00:01:26.570]There may be other survey meters on campus
- [00:01:28.820]that have different readout dial faces.
- [00:01:31.230]Make sure that you are only using
- [00:01:32.920]the counts-per-minute scale.
- [00:01:35.231]Prior to the use of any survey meter,
- [00:01:37.760]a pre-operational check must be conducted.
- [00:01:40.940]These steps are on each calibration sticker
- [00:01:43.260]located on the side of the survey meter.
- [00:01:46.340]Calibration due dates are listed by month and year.
- [00:01:50.000]The calibration is valid until the end of the month listed.
- [00:01:53.830]If you should discover a survey meter
- [00:01:55.740]out of calibration, contact EHS.
- [00:01:59.320]To start, select the battery position on the survey meter
- [00:02:02.580]and observe the needle.
- [00:02:04.290]The needle should remain
- [00:02:05.430]in the area designated on the readout dial face
- [00:02:08.240]for the battery test.
- [00:02:10.010]This can be a specific battery test range or band.
- [00:02:13.570]If the needle is out of the designated area,
- [00:02:16.160]replace the batteries and perform battery check again.
- [00:02:20.280]Next, remove the probe cover.
- [00:02:23.320]Look on the calibration sticker
- [00:02:24.850]to see what the meter check source reading should be.
- [00:02:28.130]Adjust the meter switch to the proper scale
- [00:02:30.330]to read the range given.
- [00:02:32.640]Place the probe firmly on the check source
- [00:02:35.390]and wait a few seconds to obtain a stable reading.
- [00:02:39.060]If the meter does not indicate
- [00:02:40.730]in the specific check source range value, contact EHS.
- [00:02:45.870]Finally, do not use a survey meter
- [00:02:48.910]which fails a pre-operational check.
- [00:02:51.690]Contact EHS if this occurs.
- [00:02:55.060]The lower limits for any contamination
- [00:02:57.390]are twice the background counts per minute.
- [00:03:00.570]Setup, PPE and shielding use should be in accordance
- [00:03:04.710]with approved Radiation Safety Committee protocols.
- [00:03:08.930]During radioisotope work,
- [00:03:10.790]the meter should be on the most sensitive setting
- [00:03:12.850]and placed to the side so not to interfere with experiments.
- [00:03:16.480]Work with all radioisotopes should be slow and deliberate.
- [00:03:20.370]Check your hands, equipment, and work areas periodically,
- [00:03:24.900]making sure contamination has not spread.
- [00:03:28.200]Conduct a survey of the area of interest
- [00:03:31.060]by holding the probe of the detector
- [00:03:32.870]about 1/2 inch from the surface
- [00:03:35.160]and moving the probe slowly at about two inches per second.
- [00:03:39.550]If the counts per minute increase
- [00:03:41.440]from either increased clicking
- [00:03:43.460]or by increases of the needle, slow down
- [00:03:46.510]and resurvey that area again, making sure
- [00:03:49.880]that it is not greater
- [00:03:50.970]than twice the background counts per minute.
- [00:03:54.100]If the resurveyed area is still greater
- [00:03:56.630]than twice the background counts per minute,
- [00:03:58.910]suspect contamination
- [00:04:00.620]and conduct a swipe survey of the area.
- [00:04:03.820]If the contamination is confirmed to be present,
- [00:04:06.610]the area should be decontaminated and resurveyed.
- [00:04:10.050]This is discussed in a different procedure.
- [00:04:13.320]Notify EHS in the event of a spill
- [00:04:16.100]or large area contamination.
- [00:04:18.490]Review laboratory procedures
- [00:04:20.230]including spill procedures
- [00:04:21.690]with the primary investigator or lab manager.
- [00:04:24.870]Any additional questions should be brought
- [00:04:26.940]to the attention of EHS.
- [00:04:29.860]Survey meters are to be used in laboratories
- [00:04:32.400]that use radioactive materials
- [00:04:34.040]to confirm that contamination is not being spread.
- [00:04:37.270]Periodic monitoring is a prudent step
- [00:04:39.580]towards ensuring radioactive contamination is minimized.
- [00:04:43.510](upbeat music)
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- Tags:
- radiation
- survey
- meter
- contamination
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