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Iec 61577 2 2014

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Tiêu đề Radiation protection instrumentation – Radon and radon decay product measuring instruments – Part 2: Specific requirements for 222Rn and 220Rn measuring instruments
Chuyên ngành Electrical and Electronics Engineering
Thể loại International Standard
Năm xuất bản 2014
Thành phố Geneva
Định dạng
Số trang 54
Dung lượng 469,36 KB

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Cấu trúc

  • 4.1 Design considerations for the measurements (11)
    • 4.1.1 General (11)
    • 4.1.2 Effects caused by physical properties of 222Rn and 220Rn (12)
  • 4.2 Design considerations for handling and maintenance (12)
    • 4.2.1 Portability (12)
    • 4.2.2 Application under harsh environmental conditions (12)
    • 4.2.3 Automatic operation (13)
    • 4.2.4 Reliability (13)
    • 4.2.5 Capability for operational testing (13)
    • 4.2.6 Adjustment and maintenance facilities (13)
    • 4.2.7 Acoustic noise level (13)
    • 4.2.8 Electromagnetic interference (13)
    • 4.2.9 Storage (14)
  • 5.1 Sampling assembly (14)
  • 5.2 Radiation detection assembly (14)
  • 5.3 Data processing and recording (15)
  • 5.4 Measurement display (15)
  • 5.5 Power supply (15)
  • 6.1 General (16)
  • 6.2 Standard test conditions (16)
  • 6.3 Execution of tests (16)
  • 6.4 Reference atmospheres (16)
  • 7.1 Reference response to a test source (17)
    • 7.1.1 Requirements (17)
    • 7.1.2 Test method (17)
  • 7.2 Cross-interference to other radon isotopes (17)
    • 7.2.1 Requirements (17)
    • 7.2.2 Test method (17)
  • 7.3 Linearity of indication (17)
    • 7.3.1 Requirements (17)
    • 7.3.2 Test method (18)
  • 7.4 Instrument statistical fluctuation (18)
    • 7.4.1 Requirements (18)
    • 7.4.2 Test method (18)
  • 7.5 Response time (19)
    • 7.5.1 Requirements (19)
    • 7.5.2 Test method (19)
  • 7.6 Signal accumulation (19)
    • 7.6.1 Requirements (19)
    • 7.6.2 Test method (19)
  • 8.1 General (19)
  • 8.2 Flow-rate stability (20)
    • 8.2.1 Requirements (20)
    • 8.2.2 Test method (20)
  • 8.3 Accuracy of the air flow-rate measurement (20)
    • 8.3.1 Requirements (20)
    • 8.3.2 Test method (20)
  • 8.4 Effect of filter pressure drop (20)
    • 8.4.1 Requirements (20)
    • 8.4.2 Test method (20)
  • 8.5 Indication of low sampling flow-rate (21)
    • 8.5.1 Requirements (21)
    • 8.5.2 Test method (21)
  • 9.1 Response to ambient gamma radiation (21)
    • 9.1.1 Requirements (21)
    • 9.1.2 Test method (21)
  • 9.2 Ambient temperature (21)
    • 9.2.1 Requirements (21)
    • 9.2.2 Test method (21)
  • 9.3 Relative humidity and condensed moisture (22)
    • 9.3.1 Requirements (22)
    • 9.3.2 Test method (22)
  • 9.4 Atmospheric pressure (22)
  • 10.1 Power supply variations (22)
    • 10.1.1 Requirements (22)
    • 10.1.2 Test method (22)
  • 10.2 Battery test (23)
    • 10.2.1 Requirements (23)
    • 10.2.2 Test method (23)
  • 11.1 Requirements (23)
  • 11.2 Test method (23)

Nội dung

IEC 61577 2 Edition 2 0 2014 07 INTERNATIONAL STANDARD NORME INTERNATIONALE Radiation protection instrumentation – Radon and radon decay product measuring instruments – Part 2 Specific requirements fo[.]

Design considerations for the measurements

General

To measure the activity concentration of radon isotopes 222 Rn and 220 Rn, various measurement methods can be employed The physical principles and instrument performance related to these measurements are outlined in IEC 61577-1 and ISO 11665-1.

To ensure accurate measurements, air samples must be filtered to eliminate decay products of 222 Rn and 220 Rn before reaching the detection unit's sensitive volume Additionally, when assessing the volumetric activity of 220 Rn, it is crucial to consider its extremely short half-life.

For the spot measurement of the activity concentration of radon isotopes 222 Rn and 220 Rn, grab sampling methods are employed This involves collecting an air sample by filling a container, which can be either previously evacuated or a flow-through type, and then sealing it securely.

To measure the variation of the activity concentration of 222 Rn/ 220 Rn, continuous measurement methods are used There are two sampling methods: flow-through and diffusion sampling

The air humidity may also affect the efficiency of some detectors and the instruments can be provided with air drying systems

Instrumentation that is intended to be used in field monitoring shall be portable and protected against hostile environmental conditions

The response time of the instrument shall be adequate for the variability of the phenomenon measured.

Effects caused by physical properties of 222Rn and 220Rn

The half-lives of radon isotopes vary significantly, with 222 Rn having a half-life of 3.8 days compared to 220 Rn's much shorter half-life of 55.4 seconds It is crucial to focus on the half-life of 220 Rn during air sampling and measurement processes.

To simultaneously determine the activity concentrations of 222 Rn and 220 Rn, separation techniques that leverage their distinct physical properties, including half-lives, emitted alpha-particle energies, and decay products, will be employed.

Changes in flow-rate can significantly impact the determination of activity concentration for 222 Rn and 220 Rn, particularly affecting 220 Rn measurements due to its short half-life Therefore, it is essential to measure the flow-rate when assessing the activity concentration of 220 Rn.

Design considerations for handling and maintenance

Portability

The instrument shall be portable in order to perform in-situ measurements This requires, in particular, robustness against mechanical shock.

Application under harsh environmental conditions

In harsh outdoor or workplace environments, particularly in mines, instruments must be constructed to be rugged It is essential to implement protective measures against external factors, including mechanical impacts, corrosion from solvents, solar radiation, ice formation, moisture, spraying water, and explosive atmospheres.

External influences that cannot be completely eliminated must not hinder the proper functioning of the instrument or compromise safety Additionally, spray water should not cause any harmful effects.

The manufacturer must define the minimum environmental conditions and external influences necessary for the instrument's optimal performance Additionally, they should identify any factors that could notably impair the instrument's measurement accuracy.

The manufacturer shall explicitly state whether the instrument can be used in explosive atmospheres (e.g., in mines) or not.

Automatic operation

The instrument shall be such that the measurement cycle can be carried out either manually or with programming so that automatic operation will be achievable.

Reliability

The instrument shall be designed to provide reliable performance with unrevealed failures kept to a minimum.

Capability for operational testing

Capability should be provided to allow the purchaser to carry out periodic checks on the operation of the instrument

These checks shall be carried out using one or more suitable radioactive sources as necessary.

Adjustment and maintenance facilities

The instrument must include a sufficient number of easily accessible and identifiable test points to aid in adjustments and fault detection Additionally, it should come with any necessary special maintenance tools and appropriate maintenance manuals.

The design of the instrument shall be such as to facilitate ease of repair and maintenance.

Acoustic noise level

Acoustic noise level of the instrument shall arise mainly from the sampling assembly and its resultant vibration

The manufacturer must choose components and design the instrument to ensure that the noise level remains within acceptable limits This is especially important for indoor instruments, where minimizing acoustic noise is a key consideration.

Electromagnetic interference

All necessary precautions shall be taken against detrimental effects of electromagnetic interference on or by the instrument

The manufacturer shall quantify the electromagnetic emission of the equipment The emission limits applicable to the instrument covered by this standard are given in IEC 61000-6-4

Moreover, the manufacturer shall comply with current registration on the influence of cellular phones and walkie-talkies on the instrument at a given distance and give appropriate warning.

Storage

The instrument must remain functional within the specified standards after being stored without batteries and transported in the manufacturer's packaging at temperatures ranging from –25 °C to +60 °C Additionally, it may need to meet stricter requirements, such as enduring air transportation under low atmospheric pressure.

Sampling assembly

The sampling assembly may consist of various components and functional units, including an air pump, an aerosol retention device, an air-drying device, and a flow-rate control and measurement system.

The air pump circuit must ensure sufficient airflow for accurate measurement, while being resilient to pressure fluctuations caused by operating conditions, sampling duration, filter types, and atmospheric dust accumulation All pipes and connections should be tightly sealed to maintain a consistent flow rate and prevent leaks If the air pump is a key component of the system, it should be designed for continuous operation between maintenance intervals Additionally, the flow rate should be either stabilized or accurately measured.

Most instruments use a filter to prevent 222 Rn/ 220 Rn decay products from entering the detector active volume The manufacturer shall state the type of filter

Instruments that rely on air humidity for accurate responses may include air-drying devices, such as chemical drying agents or electrically operated Peltier elements It is crucial to select a drying agent that does not adsorb 222 Rn or 220 Rn Additionally, when using chemical drying agents, their lifespan should be clearly indicated.

To ensure accurate measurements of 220 Rn activity concentration, a flow-rate control device must be implemented, featuring an adjustable range that accommodates the inherent characteristics of the air pump and filters Additionally, it is essential to provide the pressure and temperature conditions under which the flow-rate meter is calibrated for proper measurement and indication.

Radiation detection assembly

The radiation detection assembly transforms the radiation emitted by the sampled 222 Rn,

220Rn and their decay products into an electronic signal In this case, the response shall be optimized

Contamination of the detector may increase the background Precautions should be taken for the protection against airborne contamination, when the instrument is not in use

NOTE The contamination can be caused by:

– deposition of air-borne decay products;

– radioactive materials inside the relevant components of the instrument.

Data processing and recording

This assembly comprises the functional units for acquiring and processing signals supplied by the detector

The manufacturer must disclose the principles and procedures used for measurements, including the associated uncertainties This information should be detailed enough to allow the purchaser to verify the measurement results effectively.

The electronic data recording system must possess adequate capacity to capture all measurement data throughout extended automatic data-acquisition periods It is essential that the data is stored on a medium that guarantees both protection and accessibility, particularly during malfunctions, operational interruptions, or power supply failures The manufacturer is responsible for detailing the capacity of the data recording system.

Measurement display

The display must be easily readable under various ambient conditions, with clearly marked measurement units Additionally, flow-rate indication should be included if required by the measurement method.

The display shall show the activity concentration of 222 Rn/ 220 Rn

The quantities shall be given in combined SI-units Appropriate submultiples should be used

The display should show the uncertainty of the measurement

The result of the measurement shall comprise both the value attributed to the quantity to be measured and the uncertainty of the measurement associated with that value when possible

The uncertainty given should be based on the requirements of ISO/IEC Guide 98-3 to the expression of uncertainty in measurement

Data outputs must be available for remote monitoring and compatible with various devices, including displays, data recorders, printers, computers, and other devices connected through a data port.

The instrument must feature an adjustable preset threshold level that triggers a warning when the radiation quantity, such as the activity concentration of 222 Rn or 220 Rn, surpasses a predetermined value.

Power supply

The power supply subassembly shall fulfil the requirements on the protection of persons against electric shock as specified in IEC 61140

Some instruments may be equipped with batteries The batteries shall be individually replaceable The correct polarity shall be clearly indicated The manufacturer shall specify the type(s) of batteries

Rechargeable batteries must be fully charged using line power within 16 hours It is essential to include a device that automatically turns off the charger once the battery is fully charged Additionally, a clear minimum load indication should be displayed to prevent any display malfunctions.

General

General test procedures covered in this part of IEC 61577 concern instruments with different technical characteristics Except where otherwise specified, these are considered type tests

The specified requirements serve as minimum standards and can be expanded for specific equipment or functional units Acceptance tests may be defined through mutual agreement between the manufacturer and the purchaser.

A test quantity is one with which the metrological characteristics of the instrument are tested

The specification of the test quantity can also be agreed upon between the manufacturer and the purchaser.

Standard test conditions

Unless otherwise specified, the tests described in this standard shall be executed under standard test conditions which are established in a 222 Rn/ 220 Rn reference atmosphere

The standard test conditions listed in Table 1 shall be kept constant within the specified limits during a test.

Execution of tests

The activity concentration of 222 Rn and 220 Rn in the test atmosphere must produce a reading within the specified range, typically falling within the lower third of that range unless stated otherwise.

To minimize statistical fluctuations in measurements due to the inherent randomness of radioactivity, it is essential to conduct a sufficient number of measurements This approach ensures a precise average value when evaluating the instrument's conformity with relevant requirements.

To evaluate the instrument's performance for a specific influence quantity, it should be varied according to the range outlined in Table 4, while maintaining other influence quantities constant within the tolerances defined in Table 2 The relative error in the instrument's indication under reference conditions will then be calculated.

Cross-interference to other radon isotopes

Requirements

The cross-interference of 222 Rn for an instrument made for 220 Rn shall be less than 20 %

The cross-interference of 220 Rn for an instrument made for 222 Rn shall be less than 20 %.

Test method

The test shall be executed in a 222 Rn/ 220 Rn reference atmosphere established in a STAR under standard test conditions

Concerning the cross-interference of 220 Rn, the following paragraph applies

The instrument must be calibrated to measure quantities related to 222 Rn To achieve this, a sufficient amount of 220 Rn, corresponding to an activity concentration of 1,000 Bq⋅m⁻³, will be injected into the reference atmosphere and maintained for a minimum of 4 hours, ensuring that the activity concentration of 222 Rn remains negligible Following this stabilization period, the instrument will collect measurement data for at least 1 hour The results will be analyzed by calculating the ratio of the average indication during the data acquisition to the average value of the corresponding quantity for 220 Rn, expressed as a percentage.

Linearity of indication

Requirements

Linearity is evaluated through the linearity error, which measures the deviation of the output quantity curve from a straight line in relation to the input quantity This linearity error is quantified by the parameter \( Q \).

R max is the response of the instrument when the input induces an output above 90 % of the rated range;

R min is the response of the instrument when the input induces an output below 10 % of the rated range

The parameter of linearity Q shall be below 0,15 If the instrument has different working ranges the parameter of linearity shall be below 0,15 for each working range

The linearity shall be tested over the rated range of the instrument

Test method

The test shall be executed in a radon reference atmosphere established in a STAR under standard test conditions The standard test conditions shall be kept constant during the test

The true value of the test quantity should produce an instrument indication exceeding 90% of the rated range The maximum range (R max) is defined in section 3.6, while the procedure must be repeated to obtain a minimum range (R min) below 10% of the rated range Subsequently, the linearity parameter (Q) will be calculated.

If the instrument has different working ranges the procedure is to be repeated for each.

Instrument statistical fluctuation

Requirements

The results of successive measurements of the same radiation quantity shall be repeatable

The coefficient of variation attributed to the sampling and signal processing of the instrument shall not exceed 10 % Statistical fluctuations from radioactive decay shall be disregarded

Statistical fluctuations arise from the inherent randomness of radiation and radioactivity, as well as the sampling methods and signal processing used by instruments When testing for statistical fluctuations in instruments to verify measurement repeatability, it is important to note that these tests do not account for fluctuations caused by radioactive decay.

Test method

The test will be conducted in a controlled atmosphere of 222 Rn/220 Rn within a STAR, adhering to standard test conditions that remain constant throughout It will take place in the upper half of the rated range, with sampling and measurement times designed to minimize statistical fluctuations from radioactive decay to below 5%.

A minimum of 10 independent measurements must be conducted to ensure accuracy The mean value and the coefficient of variation (V) of all recorded readings will be calculated The coefficient of variation (V) associated with the instrument's sampling and signal processing is determined using a specific formula.

V = − , where V Rad is the coefficient of variation caused by the statistical fluctuation from radioactive decay

NOTE In the case of counting measurements, the coefficient of variation V Rad caused by the statistical fluctuation from radioactive decay is calculated by

In the context of measuring radiation, the gross counting rate (\(R_b\)) is compared to the background counting rate (\(R_0\)) The measurement times for the sample and background are denoted as \(t_b\) and \(t_0\), respectively When the gross counting rate significantly exceeds the background rate (\(R_b >> R_0\)), the equation simplifies to \(Rad_b \approx 1\).

Response time

Requirements

The manufacturer shall specify the response time of the assembly

NOTE This test is not relevant for instruments based on grab sampling or other short-term sampling methods.

Test method

The test will be conducted in a radon reference atmosphere defined within a STAR under standard testing conditions To achieve a step change, the instrument will be abruptly exposed to a predetermined quantity of 222 Rn/220 Rn when its activity concentration remains constant.

The response time is defined as the duration from the moment a step change occurs until the output signal first reaches 90% of its final value.

To achieve a step change in the test quantity, you can either place the instrument, which is already operational, into the test atmosphere or activate the sampling unit.

Signal accumulation

Requirements

An integrating instrument must be able to accumulate and sum both consecutive and simultaneous effects, ensuring that the measured values are stored permanently or at least for the duration of the measurement This integration can occur electronically through a signal processing system or passively via a measuring sensor that accumulates the signals.

The integrated value indicated by the instrument related to the conventionally true integrated value shall lie within the nominal tolerances given by the manufacturer.

Test method

The test shall be executed in a radon reference atmosphere established in a STAR under standard test conditions The standard test conditions shall be kept constant during the test

The time period of accumulation and integration shall be agreed upon between the manufacturer and the purchaser

8 Requirements and tests concerning air circuit performance

General

All instruments that rely on a known flow rate through their sampling and detection assemblies must undergo specific tests (refer to Table 3) If it is proven that certain tests are unnecessary for evaluating compliance with performance requirements, they may be excluded The agreement on which tests to exclude must be reached collaboratively between the manufacturer and the purchaser.

Flow-rate stability

Requirements

The manufacturer must define the airflow rate for the system Following the instrument's warm-up period, the sampling flow rate's relative error should remain within ±10% for the next 20 hours of operation.

Test method

The test shall be carried out with dust-free air in order to avoid any variation of the pressure drop of the sampling device during the test

An air flow meter calibrated under measuring conditions shall be incorporated in the air circuit in order to measure the flow-rate after 30 min, 5 h and 20 h of operation.

Accuracy of the air flow-rate measurement

Requirements

The manufacturer shall specify the accuracy of the flow-rate measurement of the air The relative error of the flow-rate measurement shall not be more than ±10 %.

Test method

A calibrated flow-rate measurement device must be included in the air circuit, ensuring that only filtered, dust-free air passes through under the instrument's standard operating conditions The accuracy of the air flow-rate measurement is critical, with attention to the relative error involved.

30 min with respect to the air flow-rate specified by the manufacturer is to be calculated.

Effect of filter pressure drop

Requirements

A pressure drop increase of 10% from the nominal value should not result in a relative error exceeding 10% in the instrument's indication under standard test conditions This relative error is assessed based on a relevant radiation quantity indicated by the instrument.

Test method

To assess the impact on the entire measurement chain, the test must be conducted in a radon reference atmosphere set within a STAR under standardized conditions It is essential to maintain these standard test conditions consistently throughout the test The quantity being tested should produce a response within the specified rated range.

Before conducting the test, ensure that a clean sampling filter is installed on the instrument Additionally, a valve should be placed downstream of the air inlet, and a calibrated pressure sensor must be attached to measure the pressure drop across both the air inlet and the valve in relation to atmospheric pressure.

EXAMPLE A U-tube or a differential manometer can be used as a pressure sensor

The pressure drop through the filter shall be measured by the pressure sensor; the indication of the instrument shall be registered

The valve must be set to achieve a pressure drop across the filter that is 10% higher than the nominal pressure drop It is essential to record the instrument's reading at this pressure drop and calculate the relative error compared to the reading at the nominal pressure drop.

Indication of low sampling flow-rate

Requirements

The system shall indicate an alarm when the indication of the sampling flow-rate goes below an acceptable level.

Test method

The system will function properly at the start of the test, but the air sampling flow rate will be decreased to a point below the established alarm threshold This will trigger an alarm.

9 Requirements and tests concerning environmental performance

Response to ambient gamma radiation

Requirements

The instrument must be engineered to minimize the impact of external gamma radiation on measurement outcomes The manufacturer is required to specify the differential change in the indicated value due to an ambient dose equivalent rate of 1 µSv/h, compared to the indicated values at both the lowest and highest limits of the rated range under standard testing conditions.

Test method

The gamma radiation test field will be generated using a 137 Cs source, ensuring an ambient dose equivalent rate of (1.0 ± 0.1) µSv/h at the reference point This rate will be uniformly distributed over a plane area larger than the detector, with the source positioned at an appropriate distance to achieve this uniformity.

The ambient dose equivalent rate of the external gamma radiation at the reference point shall be measured by a calibrated dose rate meter

During the test, the instrument to be tested shall be positioned with the detector at the reference point.

Ambient temperature

Requirements

Over the ranges of temperature specified in Table 4, the relative error shall remain within the limits specified in that table.

Test method

This test shall be executed in a radon reference atmosphere established in a STAR under standard test conditions for environmental characteristics except ambient temperature

The measurement shall begin after a thermal steady state has been reached and should last for a duration depending on the instrument characteristics

The temperature must be held at both extreme values for a minimum of one hour During the final 30 minutes of this duration, the instrument's readings should be compared to the corresponding values obtained under standard test conditions.

Relative humidity and condensed moisture

Requirements

The instrument's relative error due to humidity and condensed moisture must adhere to the limits outlined in Table 4 Testing for condensed moisture is only permitted if the manufacturer has not explicitly prohibited the instrument's use in such conditions.

Test method

The test will be conducted in a radon reference atmosphere within a STAR, adhering to standard environmental testing conditions, with the exception of ambient temperature and relative humidity Specifically, the relative humidity will be maintained at 90% while the ambient temperature is set at 30 °C Additionally, the test will be performed under thermal steady state conditions.

The test conditions must be upheld for a minimum of 1 hour, during which the instrument's readings from the last 30 minutes will be compared to the corresponding values obtained under standard test conditions.

To generate condensed moisture, the temperature must be lowered below the dew point The test conditions should be sustained for a minimum of one hour, and the instrument readings taken during the final 30 minutes of this duration will be compared to the corresponding measurements under standard test conditions.

Atmospheric pressure

Atmospheric pressure significantly affects certain types of instruments, and it is essential for manufacturers to specify the pressure conditions under which tests are conducted, along with any variations.

10 Requirements and tests concerning electrical performance

Power supply variations

Requirements

The instrument must operate on mains power with a voltage tolerance of ±10% and supply frequencies ranging from 47 Hz to 52 Hz (or 57 Hz to 62 Hz in regions with a nominal frequency of 60 Hz), ensuring that the indication does not deviate by more than ±10% from the standard test conditions.

Test method

The test will be conducted in a reference atmosphere of 222 Rn/220 Rn supplied by a STAR, ensuring that the activity concentration is suitable for the instrument to produce an indication within its rated range Additionally, a voltage test will be performed.

To ensure accurate measurements, the average of sufficient consecutive readings should be taken while the supply operates at a nominal frequency and at a voltage 10% above the nominal value This procedure must also be repeated at a voltage 10% below the nominal value.

These two mean values shall not differ from that obtained with the nominal supply voltage by more than ± 10 % b) Frequency test:

The average of sufficient consecutive readings should be recorded while the supply operates at a nominal voltage and a frequency of 47 Hz or 57 Hz, depending on whether the nominal frequency is 50 Hz or 60 Hz in the respective countries This process must be repeated at a nominal supply voltage and frequencies of 52 Hz or 62 Hz for countries with nominal frequencies of 50 Hz or 60 Hz, respectively.

These two mean values shall not differ from that obtained with the nominal frequency by more than ± 10 %.

Battery test

Requirements

The battery capacity, including that of secondary batteries, must ensure that after 8 hours of continuous use, the assembly's indication does not vary from the initial reading by more than ±10%.

Test method

An appropriate radioactive source shall be used in order to induce an indication within the rated range

The initial response shall be registered After continuous operation for 8 h, the response shall be compared with the response at the beginning of the test

11 Requirements and tests concerning mechanical performance

Requirements

The instrument shall be designed to withstand mechanical shock without degradation of performance The manufacturer shall specify the performance of the instrument with mechanical shock

The instrument must endure mechanical shocks from three perpendicular directions with an acceleration of up to 300 m⋅s\(^{-2}\) for 18 ms, characterized by a semi-sinusoidal shock pulse It should remain undamaged and fully operational in accordance with the technical standards outlined in IEC 60068-2-27.

Test method

The test methods for the mechanical types of shock are defined in IEC 60068-2-27

Each instrument shall be supplied with an appropriate manual in accordance with IEC 61187

The manual must provide essential information, including the manufacturer's name or registered trademark, relevant design characteristics of the instrument, measurement quantities and units, and details about the aerosol filter type and dimensions if applicable It should also specify the type of detector, usage instructions, effective measurement range, warm-up time, nominal air flow rate, explosion-proof qualifications, nominal power supply voltage, current consumption, and the environmental conditions for operation in compliance with the standard.

– ranges of temperature, relative humidity, atmospheric pressure;

– external electromagnetic radiation and electrostatic discharge;

The documentation will outline the anticipated operational lifespan of essential and replaceable components, including the air pump, detector, flow-rate measuring device, and batteries, based on their technical specifications.

The manual will outline the steps for assessing the instrument's performance and diagnosing technical issues It will include a comprehensive description of the maintenance procedures, ensuring that maintenance requirements are kept to a practical minimum.

13 Type test report and certificate

The results of performance tests shall be reported clearly, unambiguously and objectively

The test report will include all necessary information requested by the customer to ensure the correct implementation of the test method and accurate interpretation of the results.

A comprehensive test report must include essential details such as the laboratory's name and address, the testing location, the manufacturer's name of the tested instrument, and its relevant design characteristics Additionally, it should specify the type and serial number of the instrument, the year of manufacture, and provide a description of the test methods along with specific test conditions The report must also present the test results with appropriate units of measurement, include a statement of compliance or non-compliance with the applicable standards, and feature the names, functions, and signatures or equivalent identification of the individuals authorizing the report.

NOTE Test reports are sometimes called test certificates

Table 1 – Reference conditions and standard test conditions (unless otherwise indicated by the manufacturer)

Quantity Reference conditions Standard test conditions

Warm-up time 10 min ≥ 10 min

Activity concentration of 222 Rn b < 10 Bq⋅ m –3 < 10 Bq⋅ m –3

Activity concentration of 220 Rn c < 10 Bq⋅ m –3 < 10 Bq⋅ m –3

Atmospheric pressure 101,3 kPa 90 kPa to 106 kPa a

Power supply voltage Nominal supply voltage U N Nominal supply voltage

AC power supply frequency Nominal frequency Nominal frequency ± 0,5 %

AC power supply waveform Sinusoidal Sinusoidal with a total harmonic distortion less than 5 % Ambient dose equivalent rate < 0,20 àSv⋅h –1 < 0,20 àSv⋅h –1

Electromagnetic field of external origin Negligible Negligible

Magnetic induction of external origin Negligible Negligible

Radio frequency Negligible Less than the lowest value that causes interference

The nominal flow-rate is defined with a tolerance of ± 0.5% In cases where the detection technique is highly sensitive to atmospheric pressure variations, the conditions must be restricted to ± 0.5% of the reference pressure This specification applies exclusively to instruments measuring 220 Rn and 222 Rn.

Table 2 – Tests of the radiation detection performance

Characteristics under test Requirement Subclause

Cross-interference to 222 Rn a Response to 222 Rn ≤ 20 % 7.2

Cross-interference to 220 Rn b Response to 220 Rn ≤ 20 % 7.2

Linearity of indication Test parameter for linearity Q < 0,15 7.3

Statistical fluctuation Coefficient of variation less than ± 10 % 7.4

Response time In accordance with the manufacturer's specifications 7.5 a Only for instruments measuring 220 Rn b Only for instruments measuring 222 Rn

Table 3 – Tests of the air circuit performance

Characteristics under test Requirement Subclause

Flow-rate stability Variation less than ± 10 % in 20 h (operating hours) 8.2

Accuracy of air flow-rate Relative error regarding the indication of the instrument less than ± 10 % 8.3

Filter pressure drop Relative error regarding the indication of the instrument less than ± 10 % at an increasing pressure drop up to 10 % 8.4

Loss of sampling circuit Indicate a fault when flow-rate goes below an acceptable level 8.5

Table 4 – Tests performed with variation of influence quantities

Influence quantity Range of values Limits of variation a Subclause

Ambient dose equivalent rate ≤ 1 àSv⋅h –1 In accordance with manufacturer’s specification 9.1

Atmospheric pressure 90 kPa to 106 kPa In accordance with manufacturer’s specification 9.4

AC power supply voltage From 90 % U N to 110 % U N ± 10 % 10.1

AC power supply frequency From 47 Hz to 52 Hz

Battery capacity After 8 h of continuous operation ± 10 % 10.2

Mechanical shock is defined by the manufacturer under specific reference conditions, applicable only if not explicitly excluded This definition is relevant in countries where the nominal frequency is 60 Hz.

4 Considérations générales relatives à la conception 35

4.1 Considérations liées à la conception concernant les mesures 35

4.1.2 Effets causés par les propriétés physiques du 222Rn et du 220Rn 35

4.2 Considérations liées à la conception concernant la manipulation et la maintenance 35

4.2.2 Utilisation dans des conditions environnementales sévères 36

4.2.5 Aptitude aux essais de fonctionnement 36

4.2.6 Dispositifs de réglage et de maintenance 36

5.2 Ensemble du détecteur de rayonnement 38

5.3 Traitement et enregistrement des données 38

7 Exigences et essais concernant les performances sous rayonnement 40

7.1 Réponse de référence à une source d'essai 40

7.2 Interférence croisée avec d'autres isotopes du radon 40

8 Exigences et essais concernant les performances du circuit d'air 43

8.3 Précision de la mesure de débit d'air 43

8.4 Effet de la chute de pression dans le filtre 44

8.5 Indication d'un faible débit de prélèvement 44

9 Exigences et essais concernant les performances environnementales 44

9.1 Réponse au rayonnement gamma ambiant 44

10 Exigences et essais concernant les performances électriques 46

10.2 Essai des piles et batteries 46

11 Exigences et essais concernant les performances mécaniques 47

12 Manuel d'utilisation et de maintenance 47

13 Rapport d’essais de type et certificat 48

Tableau 1 – Conditions de référence et conditions normales d'essai (sauf indication contraire du fabricant) 49

Tableau 2 – Essais des performances de détection des rayonnements 49

Tableau 3 – Essais de la performance du circuit d’air 50

Tableau 4 – Essais réalisés avec une variation des grandeurs d’influence 50

INSTRUMENTATION POUR LA RADIOPROTECTION – INSTRUMENTS DE MESURE DU RADON ET DES DESCENDANTS DU RADON – Partie 2: Exigences spécifiques pour les instruments de mesure du 222 Rn et du 220 Rn

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La Norme internationale IEC 61577-2 a été établie par le sous-comité 45B: Instrumentation pour la radioprotection, du comité d’études 45 de l'IEC: Instrumentation nucléaire

Cette deuxième édition annule et remplace la première édition parue en 2000 La présente édition constitue une révision technique

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