Instrumentation and Measurements

The following FAQs have been developed by our topic editors for this category:

			How Can You Detect Radiation?
			Measuring Occupational Exposures
			What Dosimeter Should I Use for Personnel Monitoring?
			What Radiation Detecting Device Should I Use?

The following health physics questions have been answered by an expert and approved by our editors for inclusion in our "Ask the Experts" feature. Click on the question to see the answer.

Questions in this Category Are in the Following Subcategories:
•  Instrument Calibration (IC)
•  Surveys and Measurements (SM)
•  Personnel Monitoring (PM)
•  Miscellaneous
Instrument Calibration (IC)
Q154	–	I have several questions about HEPA filters.
Q305	–	How to handle MDA
Q807	–	Reference for counting statistics
Q1140	–	Water as a liquid scintillation fluid
Q1146	–	Black electrical tape to repair alpha probes
Q1153	–	Liquid scintillation counting
Q1221	–	Counts from a CsI:Tl detector
Q1238	–	Reduce errors in dose calibrator tests
Q1307	–	Quenching with yellow solution
Q1330	–	Gamma-ray spectroscopy
Q1367	–	measuring noble gas concentrations
Q1381	–	Determining absolute system sensitivity
Q1389	–	Photomultiplier tube efficiency
Q1591	–	Liquid scintillation counting
Q1864	–	What are the most appropriate methods for the calibration of a cesium-137 source?
Q1881	–	Why calibrate radiac devices?
Q2018	–	MDA and LLD
Q2067	–	Radon chamber
Q2299	–	Origin of Compton edge
Q2352	–	Counting U and Th minerals
Q2356	–	Reducing random errors
Q2426	–	GM dead time
Q2452	–	Background count time
Q2476	–	Convert neutron counts to dose
Q2477	–	Inverse RPG curve for neutrons
Q2478	–	Aerosol particle size neutralizer
Q2829	–	Instrument's nonlinearity
Q2834	–	Calibration for thorium-232
Q2880	–	Proportioned counter gases
Q2898	–	NaI peak widths
Q2997	–	Temperature and G-M tubes
Q3077	–	Dead time, background factors
Q3088	–	Selection of energy windows
Q3288	–	Comparison between gross alpha and alpha spectrometry values
Q3447	–	Tolerance
Q3477	–	Royal Scintillator Detector
Q3590	–	Sealed source leak testing
Q3610	–	Convert cpm to dpm
Q3642	–	Measure neutron fluence
Q3878	–	Mass attenuation coefficients
Q4882	–	Liquid scintillation counter malfunction
Q4904	–	Relative efficiency of germaniium detectors
Q4909	–	Calibrating ion chambers
Q5204	–	Efficiency for a well counter
Q5220	–	Soft x rays
Q5410	–	GM vs. ionization chamber for ion measurements
Q5421	–	Electronic personal monitor count-to-dose conversion factor
Q5440	–	Determination of activity of californium-252 source
Q5525	–	Conversion of cpm to dpm in liquid scintillation counting
Q6163	–	Using wide window for well counting
Q6694	–	Is it reasonable to use radon and progeny to determine gamma efficiencies for gaseous radionuclides?
Q6789	–	How do I calibrate the gamma counter for I-125?
Q6829	–	Are there any self-calibrating detectors?
Q6973	–	How do I maintain a fixed source-detector distance for calibration?
Q7150	–	Can I relate instrument calibration results obtained with plutonium-238 to plutonium-239 results?
Q7401	–	How do I determine efficiencies for NaI counting of environmental samples?
Q7972	–	How does detector get output converted to dose?
Q8371	–	Correlate gamma spectrum with dose
Q8495	–	Should this GM instrument meet any special requirements?
Q8505	–	What conversion factors should I use to convert between ambient dose equivalent and air kerma?
Q8629	–	Low Energy Response of GAFCHROMIC EBT Film
Q8865	–	TLD-100 for high-energy photons
Surveys and Measurements (SM)
Q65	–	I want a device to monitor radioactive contamination.
Q96	–	When should I use a pancake probe instead of a survey meter probe?
Q204	–	Forward information on very high-dose detectors.
Q209	–	How do CdTe and NaI detectors work?
Q253	–	Patient surveys following administration of beta emitters
Q263	–	Swipe surveys in remote areas
Q323	–	Collection efficiencies for swipe materials
Q438	–	Meter for measuring cobalt-58
Q463	–	Pancake probes vs. ion chambers
Q534	–	Alpha, beta, and gamma detectors
Q628	–	CDV-777 kits
Q688	–	Phosphor GR200
Q761	–	GM tubes
Q883	–	Detector to respond to alpha, beta, and gamma
Q992	–	Automated Transportation Indexing System
Q1069	–	Gamma-radiation measurements
Q1111	–	GM survey meter to measure betas
Q1151	–	Detector for mine tailings environment
Q1208	–	Radon and Geiger counters
Q1225	–	Pancake probe to check for technetium-99 contamination
Q1309	–	X-ray unit exposure rate determination
Q1405	–	Narrow beam measurements with a GM tube
Q1425	–	Measuring carbon-14 and hydrogen-3
Q1620	–	Radon monitoring
Q1648	–	Depleted uranium swipes
Q1649	–	Pancake probes
Q1712	–	NaI crystal and survey meter
Q1751	–	X-ray emissions from CRT
Q1787	–	Emissions from stacks
Q1981	–	Alpha scintillation
Q2134	–	Nuclear density gauge
Q2320	–	X-ray diffraction unit leakage
Q2391	–	Contamination surveys
Q2522	–	Radionuclide identification
Q3012	–	Gamma/beta fields
Q3036	–	Using liquid scintillation to measure a gamma emitter
Q3052	–	Measure strontium-90 in the human body
Q3128	–	Stack monitoring
Q3280	–	Radon measurements
Q3467	–	Monitor-4
Q3580	–	How does GM counter measure rem?
Q3644	–	Detectable dpm
Q3760	–	Counting cadmium-109 and carbon-14
Q3800	–	Radiation surveys in radiology rooms
Q3906	–	Well counting spill correction
Q4026	–	Air monitoring sample points
Q4067	–	Water sample and public dose limit
Q4088	–	Need preamplifier and MCA
Q4148	–	Convert from counts to dose
Q4202	–	Will a space heater affect the readings of a continuous radon monitor?
Q4305	–	Shielding in a diagnostic x-ray facility ceiling
Q4316	–	Plastic gamma detectors
Q4338	–	Geiger-Müller
Q4495	–	Survey of nuclear power plant materials
Q4713	–	Background counts by G-M
Q4796	–	Calibrate TLD-100 chips
Q4934	–	Reaching equilibrium
Q4936	–	Contamination surveys
Q4943	–	Over response of G-M detectors
Q5069	–	Chi-square test
Q5388	–	Causes of transient responses in air ionization chambers
Q5521	–	Quenching by silicone greaser from tritum bubbler
Q5799	–	Determination of volume and area concentrations of radionuclides
Q5818	–	Palladium-103 implant monitoring
Q5897	–	Wipe methods for tritium surface contamination
Q5982	–	Why is chi-square range so wide?
Q6104	–	Gamma detectors for radionuclide identification
Q6161	–	What is the source of this 140 keV contaminant in Tc-99m?
Q6174	–	What causes change in ionization chamber leakage?
Q6213	–	Should I expect ion chamber measurement problems for a pulsed x-ray source?
Q6292	–	Is GM detector dead time affected by type of radiation?
Q6443	–	Sampling and measuring carbon-14 in groundwater
Q6457	–	How do I position a fixed area monitor and establish alarm set point?
Q6506	–	What detector should I use to detect radiations from rocks?
Q6571	–	What causes large variations in wipe analyses for tritium?
Q6593	–	What does energy range refer to in survey instrument descriptions?
Q6655	–	How can I differentiate among different PET nuclides in a mixture of such radionuclides?
Q6701	–	How do I decide whether this object is contaminated?
Q6820	–	Differences in detector efficiencies and background responses
Q6899	–	Will this 0.1 mm wall, air-filled GM detector respond to alpha radiation?
Q6937	–	Alpha detector efficiency
Q6965	–	Convert TLD entrance skin dose to effective dose
Q6984	–	Instruments to detect orphan sources
Q6998	–	Are instruments available that directly measure surface contamination levels?
Q7119	–	Instrumentation for measuring beta-gamma emitting contamination
Q7168	–	Can I separate these photon energies from 111In using a well counter?
Q7240	–	Can I convert the count rate on this detector to radon concentration?
Q7241	–	Is this GM probe able to measure this surface contamination level?
Q7387	–	How can I measure zinc 65 contamination?
Q7413	–	Are wireless environmental monitoring systems available?
Q7442	–	Small dimension alpha probes
Q7449	–	Measure x rays with GM detector
Q7500	–	Correlate count rate on GM with technetium-99m skin activity
Q7530	–	Spillover between alpha and beta channels in proportional counter
Q7546	–	Lead-214 and bismuth-214 gamma rays for radium-226 determination
Q7605	–	Surface contamination measurements and need for respiratory protection
Q7763	–	Why bother with the reduced chi-square value?
Q7823	–	Is radium-226 analysis by gamma spectrometry reliable?
Q7958	–	Does this chi-square value show system
Q7973	–	How is transport index determined?
Q7986	–	Is residual bomb radioactivity visible by satellite imaging?
Q8067	–	Why is the manufacturer’s measurement range different from the display range for this GM?
Q8079	–	How do I correlate GM exposure rate and count rate on gamma camera?
Q8149	–	How does the guard ring reduce leakage in ion chamber?
Q8162	–	Multiuse contamination detector
Q8184	–	What GM response should I expect from this Na-22 source?
Q8227	–	How do I use this NaI detector to measure RDD ground contamination?
Q8263	–	Why are these package surface dose rates different?
Q8288	–	Is this attenuation method legitimate for beta radionuclide identification?
Q8308	–	What dosimeters can be used to measure reactor in-core doses?
Q8437	–	How do I obtain dose rate from count rate for this neutron instrument?
Q8446	–	Average photon energy from reactor pulse height distribution.
Q8558	–	What 9-inch ball was used for the 9-inch/3-inch method for neutron energy assessment?
Q8597	–	Use of thorium-232 progeny to determine thorium activity
Q8600	–	Is the pancake detector suitable for screening purposes in leak testing?
Personnel Monitoring (PM)
Q11	–	Which materials must have a criticality dosimeter and why?
Q22	–	Optically stimulated luminescence.
Q312	–	At what temperature will a TLD's accuracy be compromised?
Q353	–	Availability of pocket dosimeters
Q375	–	Measuring doses: mammography, beta emitters, and fetal.
Q377	–	Film badges for personnel monitoring.
Q567	–	Skin contamination
Q644	–	Monitoring for phosphorus isotopes
Q847	–	Radiochromic film dosimetry
Q871	–	Are medical doses included in occupational doses?
Q908	–	Analysis of film
Q994	–	Social security numbers for exposure databases
Q1220	–	Respirator fit testing
Q1279	–	Personnel monitoring
Q1436	–	Pocket dosimeter and TLD badge
Q1613	–	TLDs
Q1726	–	TLD-100 for gamma measurements
Q1771	–	OSL exchange frequency
Q1931	–	LiF compared with NaI(Tl) as a TLD
Q2072	–	Credit-card-type detector
Q2075	–	Sales people at hospitals
Q2091	–	Where to wear a film badge dosimeter
Q2092	–	Film badge location
Q2186	–	Dosimeters
Q2303	–	Glass dosimeters
Q2392	–	Airborne concentration
Q2986	–	TLD-100H
Q3142	–	Converting rad to rem
Q3557	–	Optically stimulated luminescence
Q3801	–	Masking of neutron dose by gamma dose
Q4129	–	Badge that changes color
Q4321	–	How does TLD (thermoluminescent dosimetry) work?
Q4417	–	Geiger counter and nuclear power plant accident
Q4942	–	Radiation emitted by the human body
Q5225	–	TLD 100 and TLD 700H
Q5413	–	Photon energy dependence in calibration and response of LiF
Q5429	–	What constitutes whole body in whole-body monitoring?
Q5714	–	How to clean TLDs
Q6140	–	Integrated response
Q6215	–	What is the significance of the readings on the dosimeter I am wearing?
Q6266	–	Why is there a different light output for preintegrate portion of readout cycle for TLD-100h vs. TLD-100?
Q7249	–	Radium in the body
Q7624	–	Personnel dose measurement in medical facilities
Q7966	–	What TLD shape is appropriate?
Q8191	–	Is there a dosimeter I can use to measure my public exposure?
Q8543	–	Can you provide sources for information about personnel dosimetry and biodosimetry?
Q8622	–	Neutron albedo—men vs. women
Q8689	–	Training to remove the liquid scintillation counter external standard source
Miscellaneous
Q114	–	What type of probe device should be used for respirator fit testing?
Q129	–	Are TLDs sensitive to light? How safe is the glowing water in a reactor?
Q229	–	How are plutonium and uranium detected in the body?
Q242	–	Ar-41 formation in HPIC due to thermal neutrons
Q266	–	How do I determine the concentration of radium-226 in a sample?
Q268	–	Grand Canyon measurements
Q272	–	What is the relationship between 6 pCi/L wet to 6 pCi/g dry radium?
Q386	–	Alpha, beta, and gamma radiation
Q700	–	Minimum sensitivity of an instrument
Q860	–	False CAM alarms
Q907	–	Good instruments or door stops?
Q989	–	Lithium glass detectors
Q1136	–	CR-39 supplier
Q1197	–	How to handle phosphorus-32 and iodine-125
Q1198	–	Time-dependent version of the MCNP Code
Q1244	–	Vendors of radiation detection devices
Q1293	–	Fission Chamber
Q1300	–	Perkin-Elmer cathode lamps
Q1366	–	Correction for Hg expansion
Q1510	–	Detectors that change color
Q1543	–	Radioactivity in concrete
Q1590	–	Purchase GM Tube
Q1685	–	Disposal of contaminated tubes
Q1784	–	GM spreadsheet
Q2029	–	Attenuation factor for a vehicle
Q2199	–	15 keV x rays
Q2200	–	Germanium detector
Q2254	–	Old civil defense equipment
Q2255	–	Operation of G-M Counters
Q2339	–	Americium-241 in moisture density gauges
Q2393	–	Volatility of iodine
Q2394	–	Proportional counter
Q2444	–	Settling tank sensors
Q2461	–	Percent error for LiF TLDs
Q2548	–	Convert pCi to mg
Q2562	–	C-14 measurement
Q2774	–	Gamma sterilizing
Q3032	–	Research facility design parameters
Q3041	–	Radioactivity measurements in a data center
Q3156	–	Testing of HEPA units
Q3180	–	Landfill radiation monitoring
Q3457	–	Doses from californium-252
Q3475	–	Air filtration system
Q3497	–	Build a Geiger counter
Q3511	–	Air cleaner
Q3568	–	Beta protection with a polymer
Q3893	–	Silicon PIN diode
Q4033	–	Medical x-ray machine
Q4098	–	Proportional counters to detect x rays
Q4547	–	Resolution of an NaI(Tl) detector
Q4854	–	Boron-treated neutron detector
Q5368	–	QA/QC for gamma spectroscopy
Q5561	–	Radiochromic film for low- and high-energy photons
Q5754	–	Annealing cycle for LiF TLD-100
Q5855	–	Gamma energy and detector resolution
Q5920	–	Improve charge neutralization of aerosol particles
Q5958	–	Declare equipment clean
Q6320	–	Origin of the name
Q6494	–	How do I repair or dispose of this gamma counter?
Q6500	–	Degradation of liquid scintillation standards
Q6698	–	Membrane testing for radionuclide penetration
Q6711	–	Is it okay to dispose of this civil defense G-M in the trash?
Q6886	–	Is CR-39 a tissue-equivalent dosimeter material?
Q7153	–	How do I convert tissue dose to silicon dose?
Q7531	–	Volume reduction to measure radioactivity in oil
Q7692	–	Response of MOSFET dosimeter
Q8032	–	Will light from this glass scintillator be visible?
Q8165	–	Will gamma radiation damage this glass scintillator?
Q8177	–	What container is suitable to analyze solid samples for radium?

The following Web sites may also be useful:

			Accredited Radiation Laboratories (NIST)
			IAEA Safety Series No 16 "Calibration of Radiation Protection Monitoring Instruments"
			Laboratory Procedures (MARLAP)
			Measuring Radioactivity (EPA/MARSSIM)
			Radiation Detection Textbook (Knoll)
			Radiation Measurements (Idaho State University)
			Radiation Procedures Manual (DOE)
			Radiological Surveys (NRC)
			Radionuclides in Chemistry (Wiley)