2012–......  1 Nicht löschen bitte "" !! Ordinance of the FDJP  
on Measuring Instruments for Ionising Radiation 
 
 
 
(“StMmV”)  
of … 
 
The Federal Department of Justice and Police, 
based on Articles 5, 7 Paragraph 2, 8 Paragraph 2 a nd 9 Paragraph 3 of the Federal 
Act of 17 June 2011 1 on Metrology, 
Articles 5 Paragraph 2, 8 Paragraph 2, 16 Paragraph  2, 17 Paragraph 2, 24 Paragraph 
3 and 33 of the Measuring Instruments Ordinance of 15 February 2006 2 
as well as Articles 64 and 112 of the Radiological Protection Ordinance of 22 June 
1994 3 (“StSV”), 
hereby decrees:  
Section 1: General provisions 
Art. 1  Object 
This ordinance concerns: 
a. Requirements for measuring instruments for ionis ing radiation; 
b. Procedures for  placing on the market such measu ring instruments; 
c. Procedures to preserve measurement stability of such measuring instru- 
ments. 
Art. 2  Scope 
This ordinance applies to: 
a. Mobile reference measuring systems (therapy dosi meters), consisting of an 
ionisation chamber, electrometer and control curren t equipment, which are 
used to measure the dose or dose rate of photon, el ectron and hadron radia- 
tion in radiotherapy systems; 
b. Surface contamination monitors for personal, wor kplace and material moni- 
toring in the area under supervision of the Swiss F ederal Nuclear Safety In- 
  
 SR ..........  
1 SR ... [BBl 2011  4865] 
2 SR 941.210  
3 SR 814.501 Ordinance AS 2012 
2 spectorate (ENSI) and in work areas of laboratories  of types B and A in ac- 
cordance with Article 69 StSV 4 in the area under supervision of the Federal 
Office of Public Health (FOPH) and the Swiss Nation al Accident Insurance 
Organisation (SUVA); 
c. Dose calibrators which are based on the well-typ e ionisation chamber prin- 
ciple and used in nuclear medicine laboratories to measure the activity of 
open radioactive sources intended for medical appli cations; 
d. Radiation protection measuring instruments for e xternal radiation for moni- 
toring local dose rates in the vicinity of nuclear power plants (“MADUK 
system”), for monitoring local dose rates in Switze rland (“NADAM sys- 
tem”), for workplace and material monitoring of loc al dose rates in the area 
under supervision of the ENSI, and at locations in the area under supervision 
of the FOPH and SUVA where local dose rates > 100 µSv/h are expected; 
e. Well-type ionisation chamber systems used to mea sure the source strength 
of Ir-192 sources for HDR brachytherapy; 
f. Measuring instruments used for acceptance testin g and regular status checks 
of X-ray diagnostic equipment: 
1. Diagnostic dosimeters,  
2. kV meters,  
3. mAs meters,  
4. Exposure time meters,  
5. Sensitometers,  
6. Densitometers, 
7. Photometers and luxmeters; 
g. Radon measuring instruments for official measure ments by FOPH-approved 
measurement offices; 
h. Radon dosimeters for official measurements by FO PH-approved measure- 
ment offices. 
Art. 3  Definitions  
The definitions contained in Annex 1 apply in this ordinance.  
Section 2: Mobile reference dosimeter systems for r adiotherapy 
Art. 4  Fundamental  requirements 
Mobile reference dosimeter systems for radiotherapy  must fulfil the fundamental 
requirements in accordance with Annex 1 of the Meas uring Instruments Ordinance 
and Annex 2 of this present ordinance. 
  
4 SR 814.501  Ordinance AS 2012 
3 Art. 5  Procedure for placing on the market 
Mobile reference dosimeter systems for radiotherapy  require proper approval and 
initial verification in accordance with Annex 5 of the Measuring Instruments Ordi- 
nance and Annex 2 of this present ordinance. 
Art. 6  Procedure to preserve measurement stability 
Mobile reference dosimeter systems for radiotherapy  must be reverified  every four 
years in accordance with Annex 7 Point 1 of the Mea suring Instruments Ordinance 
and Annex 2 of this present ordinance, by METAS or an authorised verification 
centre.  
Section 3: Surface contamination monitors 
Art. 7  Fundamental  requirements 
Surface contamination monitors must fulfil the fund amental requirements in accord- 
ance with Annex 1 of the Measuring Instruments Ordi nance and Annex 3 of this 
present ordinance. 
Art. 8  Procedure for placing on the market  
Surface contamination monitors require proper appro val and initial verificationin 
accordance with Annex 5 of the Measuring Instrument s Ordinance and Annex 3 of 
this present ordinance. 
Art. 9  Procedure to preserve measurement stability 
Surface contamination monitors must be reverified e very three years in accordance 
with Annex 7 Point 1 of the Measuring Instruments O rdinance and Annex 3 of this 
present ordinance, by METAS or an authorised verifi cationcentre.  
Section 4: Dose calibrators 
Art. 10  Fundamental requirements 
Dose calibrators must fulfil the fundamental requir ements in accordance with Annex 
1 of the Measuring Instruments Ordinance and Annex 4 of this present ordinance. 
Art. 11  Procedure for placing on the market 
Dose calibrators require proper approval and initia l verificationin accordance with 
Annex 5 of the Measuring Instruments Ordinance and Annex 4 of this present ordi- 
nance. Ordinance AS 2012 
4 Art. 12  Procedure to preserve measurement stability 
Dose calibrators must be  reverified annually eithe r in accordance with Annex 7 
Point 1 of the Measuring Instruments Ordinance and Annex 4 of this present ordi- 
nance, by METAS or an authorised verificationcentre , or undergo a comparison 
measurement in accordance with Annex 7 Point 4 of t he Measuring Instruments 
Ordinance and Annex 4 of this present ordinance, by  METAS or an authorised 
verificationcentre. Dose calibrators must be reveri fied at least every three years in 
accordance with Annex 7 Point 1 of the Measuring In struments Ordinance and 
Annex 4 of this present ordinance, by METAS or an a uthorised verificationcentre.  
Section 5: Radiation protection measuring instrumen ts for external 
radiation 
Art. 13  Fundamental  requirements 
Radiation protection measuring instruments for exte rnal radiation must fulfil the 
fundamental requirements in accordance with Annex 1  of the Measuring Instruments 
Ordinance and Annex 5 of this present ordinance. 
Art. 14  Procedure for placing on the market 
Radiation protection measuring instruments for exte rnal radiation require proper 
approval and initial verificationin accordance with  Annex 5 of the Measuring In- 
struments Ordinance and Annex 5 of this present ord inance. 
Art. 15  Procedure to preserve measurement stability 
Radiation protection measuring instruments for exte rnal radiation must be reverified 
every three years in accordance with Annex 7 Point 1 of the Measuring Instruments 
Ordinance and Annex 5 of this present ordinance, by  METAS or an authorised 
verificationcentre.  
Section 6: Well-type ionisation chamber systems for  Ir-192 HDR 
brachytherapy 
Art. 16  Fundamental requirements 
Well-type ionisation chamber systems for Ir-192 HDR  brachytherapy must fulfil the 
fundamental requirements in accordance with Annex 1  of the Measuring Instruments 
Ordinance and Annex 6 of this present ordinance. 
Art. 17  Procedure for placing on the market 
Well-type ionisation chamber systems for Ir-192 HDR  brachytherapy require proper 
approval and initial verificationin accordance with  Annex 5 of the Measuring In- 
struments Ordinance and Annex 6 of this present ord inance. Ordinance AS 2012 
5 Art. 18  Procedure to preserve measurement stability 
Well-type ionisation chamber systems for Ir-192 HDR  brachytherapy must be rever- 
ified every four years in accordance with Annex 7 P oint 1 of the Measuring Instru- 
ments Ordinance and Annex 6 of this present ordinan ce, by METAS or an author- 
ised verificationcentre.  
Section 7: Diagnostic dosimeters and measuring inst ruments for 
checking X-ray diagnostic equipment 
Art. 19  Fundamental requirements 
Diagnostic dosimeters and measuring instruments for  checking X-ray diagnostic 
equipment must fulfil the fundamental requirements in accordance with Annex 1 of 
the Measuring Instruments Ordinance and Annex 7 of this present ordinance. 
Art. 20  Procedure for placing on the market 
Diagnostic dosimeters and measuring instruments for  checking X-ray diagnostic 
equipment require proper approval and initial verif icationin accordance with Annex 
5 of the Measuring Instruments Ordinance and Annex 7 of this present ordinance. 
Art. 21  Procedure to preserve measurement stability 
Diagnostic dosimeters and measuring instruments for  checking X-ray diagnostic 
equipment must be reverified every three years in a ccordance with Annex 7 Point 1 
of the Measuring Instruments Ordinance and Annex 7 of this present ordinance, by 
METAS or an authorised verificationcentre.  
Section 8: Radon measuring instruments 
Art. 22  Fundamental requirements 
Radon measuring instruments must fulfil the fundame ntal requirements in accord- 
ance with Annex 1 of the Measuring Instruments Ordi nance and Annex 8 of this 
present ordinance. 
Art. 23  Procedure for placing on the market 
Radon measuring instruments require proper approval  and initial verificationin 
accordance with Annex 5 of the Measuring Instrument s Ordinance and Annex 8 of 
this present ordinance. Ordinance AS 2012 
6 Art. 24  Procedure to preserve measurement stability 
Radon measuring instruments must be reverified ever y four years in accordance with 
Annex 7 Point 1 of the Measuring Instruments Ordina nce and Annex 8 of this pre- 
sent ordinance, by METAS or an authorised verificat ioncentre.   
Section 9: Radon dosimeters 
Art. 25  Fundamental requirements 
Radon dosimeters must fulfil the fundamental requir ements in accordance with 
Annex 1 of the Measuring Instruments Ordinance and Annex 9 of this present ordi- 
nance. 
Art. 26  Procedure for placing on the market 
Radon dosimeters require proper approval in accorda nce with Annex 5 of the Meas- 
uring Instruments Ordinance. 
Art. 27  Procedure to preserve measurement stability 
Radon dosimeters must undergo a comparison measurem ent every two years in 
accordance with Annex 7 Point 4 of the Measuring In struments Ordinance, by 
METAS or an authorised verificationcentre.  
Section 10: Concluding provisions  
 
Art. 28  Repeal of previous legislation 
The Ordinance of the FDJP of 29 November 2008 5 on Radon Measuring Instruments 
is hereby repealed. 
Art. 29  Transitional provisions 
1 Measuring instruments for ionising radiation that were placed on the market prior 
to the entry into force of this ordinance and which  are reported to METAS by the 
verificationcentres within six months after the ent ry into force of this ordinance are 
deemed to be approved. 
2 Measuring instruments for ionising radiation in ac cordance with Article 2 Letters 
a–g that were reverified prior to the entry into fo rce of this ordinance may be used 
until the validity of the last reverification expir es. Thereafter, such instruments must 
be reverified in accordance with Articles 6, 9, 12,  15, 18, 21 or 24. 
  
5 AS 2009  179 Ordinance AS 2012 
7 3 Radon dosimeters that underwent a comparison measu rement prior to the entry into 
force of this ordinance may be used until the perio d specified at the last comparison 
measurement expires. Thereafter, they must undergo comparison measurement in 
accordance with Article 27. 
Art. 30  Entry into force 
This ordinance enters into force on 1 January 2013.  
...  Federal Department of Justice and Police:  
 Simonetta Sommar uga  
 Ordinance AS 2012 
8 Annex 1 
(Art. 3) 
Definitions 
In this ordinance, the following definitions apply:  
 Dose calibrator:  Measuring instrument for determining the activity of open 
radioactive sources intended for medical usage; 
 Activity:  Number of decays per time unit. The unit of activi ty is the becque- 
rel (Bq); 
 Becquerel (Bq):  SI unit for the activity of a radionuclide. 1 Bq =  1 decay per 
second; 
 Beta emitter:  Radioactive source that emits ionising radiation p rimarily in 
the form of electrons; 
 Densitometer:  Measuring instrument for determining the optical d ensity of 
X-ray film for X-ray diagnostic equipment; 
 Diagnostic dosimeter:  Electronic dosimeter for determining the radiation  
intensity of X-ray diagnostic equipment; 
 Dose, absorbed dose:  Energy deposited in a mass unit due to interaction  of 
ionising radiation with a medium. The relevant unit  is the gray (Gy); 1 Gy = 
1 J/kg; 
 Dose rate:  Dose per time unit; 
 Electrometer:  Measuring instrument for determining the electrica l charge 
generated in an ionisation chamber due to absorptio n of ionising radiation; 
 Electron beam radiation:  Ionising radiation consisting of high-energy elec-
trons (> 1 MeV); 
 Exposure time meter:  Measuring instrument for determining the exposure 
time of X-ray diagnostic equipment; 
 External radiation:  Ionising radiation that acts upon the body from ou tside; 
 Gamma emitter:  Radioactive source that emits ionising radiation p rimarily 
in the form of photons; 
 Gray (Gy):  SI unit for absorbed dose of ionising radiation. 
1 Gy = 1 J/kg; 
 Half-value depth  (R50):  The distance in a water phantom at which the inten - 
sity of electron beam radiation decreases by half; 
 Ionisation chamber:  Measuring instrument for determining the intensity  of 
ionising radiation through ionisation of the air co ntained therein and corre- 
sponding generation of free electrical charge carri ers; 
 Ir-192 HDR brachytherapy:  Radiotherapy in which an enclosed radiation 
source of Ir-192 is placed inside or close to the a rea of the body under treat- 
ment;  Ordinance AS 2012 
9  (Radioactive) control equipment:  Radioactive source for generating a known 
radiation intensity in order to check the constancy ; 
 Constancy test:  Measurement technique for checking the constancy o f a 
measuring system in terms of time;  
 Control current:  Electrical current generated by an ionisation cham ber as 
part of a constancy test; 
 kV meter:  Measuring instrument for determining the high volt age in X-ray 
diagnostic equipment;  
 Air kerma:  Energy released per mass unit in air due to photon  radiation; 
 mAs meter:  Measuring instrument for determining the accumulat ed charge 
of the diagnostic meter in X-ray diagnostic equipme nt;  
 Nuclide:  A single specific atomic species defined by its at omic number 
(number of protons) and nuclear number; 
 Residual current:  Current measured by an electrometer connected to a n ioni- 
sation chamber in the absence of ionising radiation ; 
 Surface contamination:  Contamination of the surface of a material with ra - 
dioactive substances; 
 Surface contamination monitor:  Measuring instrument for determining the 
surface contamination; 
 Local dose, local dose rate:  The ambient dose equivalent H*(10) or its time-
dependent intensity at the point of interest in the  radiation field; 
 Mobile reference measuring system:  Measuring system in a radiotherapy 
centre that is used as a local reference system for  determining the patient 
dose and which consists of an ionisation chamber, e lectrometer and control 
current equipment; 
 Photometer/luxmeter:  Measuring instrument for determining the light int en- 
sity in darkrooms of X-ray diagnostic equipment; 
 Photon radiation:  Ionising radiation consisting of high-energy photo ns (> 1 
MeV); 
 Test source:  Radioactive source for generating a known radiatio n intensity 
in order to check the constancy of radiation measur ing instruments; 
 Source strength:  Activity (in Bq) of a radioactive source; 
 Radionuclide:  Nuclide that decays spontaneously while emitting r adiation; 
 Radon activity concentration:  Radon activity per volume unit; 
 Radon dosimeter:  Measuring instrument for determining radon exposur e; 
 Radon exposure:  Product of radon activity concentration and time; 
 Radon measuring instrument:  Measuring instrument for determining the ra- 
don activity concentration; Ordinance AS 2012 
10  Reference source:  Radioactive source for generating a known radiatio n in- 
tensity in order to check the constancy of radiatio n measuring instruments; 
 Guide value:  General term for a radiation intensity value which  is derived 
from a limit value and which, if exceeded, requires  certain measures to be 
instituted and which, if complied with, also ensure s compliance with the as- 
sociated limit value; 
 X-ray diagnostic equipment:  X-ray system and associated imaging and im- 
age-processing systems; 
 X-ray radiation:  Ionising radiation consisting of low-energy photon s 
(10 keV to 300 keV); 
 Well-type ionisation chamber:  Cylindrical ionisation chamber with an open- 
ing on the axis for insertion of the material to be  tested; 
 Sensitometer:  Measuring instrument for determining the sensitivi ty of X-ray 
film for X-ray diagnostic equipment; 
 Radiation quality:  Designator for the spectral composition of electro n, pho- 
ton and X-ray radiation. Ordinance AS 2012 
11 Annex 2 
(Art. 4–6) 
Mobile reference dosimeter systems for radiotherapy  
1 Construction, metrological characteristics 
 Each system consists of an ionisation chamber, an electrometer and radioac- 
tive control equipment. The construction and metrol ogical characteristics of 
these components must conform to the state of the a rt and the intended 
application, particularly as expressed in the Ordin ance on Medical Devices 
of 17 October 2001 6 (“MepV”).  
2 Verification 
2.1 For the verification, the systems must include operating instruc tions with 
technical specifications.  
2.2 During the verification, the system is checked for correct opera tion and 
calibrated. The radioactive control equipment is ev aluat ed and the display 
corresponding to the control current (control displ ay) is recorded in the 
verification certificate.  
2.3 The system is approved for use if it can be calibra ted with a relative total 
measurement uncertainty within ± 3% (± 4% for soft X-ra y radiation with 
generation voltages less than or equal to 100 kV) a t a confidence level of 
95%.  
2.4 During verification for photon radiation, the syste m must be calibrated at the 
radiation qualities for which it is used. Calibrati on is performed as close as 
possible to these qualities. In general, calibratio n is performed at only one 
dose rate value for each quality. 
During verification for electron beam radiation, th e half-value depths at 
which calibration of the systems is performed, taki ng into account the 
METAS measurement capabilities, are selected as fol lows: Each half- value 
depth R50 at which the system is used must lie betw een two half- value 
depths at which calibration is performed, and their  difference may have a 
maximum value of 2 g·cm -2. In general, calibration is performed at only one 
dose rate value for each quality.  
3 Error limits at inspections 
3.1 If the systems are used more frequently than on ce per half- year, they must 
be checked at least semi-annually with the control equipment for corr ect 
operation and constancy. Otherwise, such checking m ust be performed in 
each case prior to usage. 
Air density correction for the test with the radioa ctive control equipment 
must be performed for accuracy of at least ± 0.3% ( confidence level: 95%) 
  
6 SR 812.213 Ordinance AS 2012 
12 using a traceably calibrated thermometer and barometer. D uring testing of 
this sort, at least the following data must be reco rded in writing: 
- Date of test, initials of person who performs it,  
- Identification of electrometer, chamber, adapter and radioactive c ontrol 
equipment, 
- Control display, display corresponding to residua l current (including leak- 
age current) before and after the control current m easurement along with 
temperature and air pressure, 
- Control display corrected for air density (to T0 = 293.15 K, p0 = 1013.25 
hPa) as well as the control display converted to th e date of the test and 
spec ified in the verification certificate.  
3.2 During the constancy test, the control display is a llowed the following 
maximum deviation from the value recorded in the verification certificate 
and converted to the date of the test: 
- 1.5% for soft X-ray radiation ( ≤ 100 kV) 
- 0.5% for hard and high-energy photon radiation (>  100 kV) 
- 1.0% for electron beam radiation  
Otherwise, the verification shall cease to be val id.  
4 Validity of the verification 
 The verification is valid for a period of four year s. METAS may lengthen or 
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instrumen ts used 
allow or require such treatment.  
 Ordinance AS 2012 
13 Annex 3 
(Art. 7–9) 
Surface contamination monitors 
1 Construction, metrological characteristics 
1.1 The construction and metrological characteristi cs of the devices must con- 
form to the state of the art and the int ended application.  
1.2 The devices must display a multiple of the nucl ide-specific guide value for 
the contamination (Annex 3 of the Radiation Protect ion Ordinance) or the 
counting rate. In case of display of a multiple of the nuclide- specific guide 
value , it must also be possible to alternatively read of f the counting rate.  
1.3 If devices display only the counting rate, the net counting rate which corre- 
sponds to a guide value (guide value counting rate,  “RWZ”) must be clearly 
indicated on the device for a nuclide under observation.  
2 Verification 
2.1 For the verification, the devices must include operating instruc tions with 
technical specifications and a list of nuclides for  which the device must be 
verified.  
2.2 During the verification, a check is mad e whether for a specific surface 
activity of a given nuclide, the measurement result lies within the specified 
verification error limit.  
2.3 The test sources to be used during the regular chec ks of the devices are 
evaluated during each verification and th e values that are measured are 
re corded in the verification certificates.  
2.4 The verification covers the device’s measurement ra nges which contain the 
guide values for the nuclides used in the verificat ion.  
2.5 For devices with a fixed measurement time (e.g. output monitors), a check is 
made whether contamination corresponding to the gui de value is displayed 
within the defined measurement time.  
2.6  The verification error limits are equal to ± 50%.  
3 Error limits at inspections 
 If, during an official inspection outside of the verification, the device’ s 
measurement error is greater than the verification erro r limit, the verification 
shall cease to be valid.  
4 Verification procedure  
4.1 The surface emission rates of the radioactive r eference sources us ed in the 
verification form the basis for the verification of  the devices. The verifica- 
tion is referred to the active surface of the refer ence source of 100 cm 2. 
4.2 The guide value counting rate (“RWZ”) is the re ference quantity. Computa- 
tions of this qua ntity must be based on   Ordinance AS 2012 
14 RWZ = CS · W · Σj ( εi,j · εd,j · εs,j) 
where 
εi,j : Sensitivity or surface emission response of a  device for radiation type j,  
εd,j : Emission frequency of a given nuclide for rad iation type j,  
εs,j : Surface emission rate of a contamination sour ce divided by the genera- 
tion rate of particles or photons of the same radia tion type j, where  
εs = 0.5 for γ-sources as well as for β-sources with Eaverage ≥ 140 keV 
εs = 0.25 for β-sources with 40 keV < Eaverage < 140 keV and for α-
sources, 
W : Active area of the reference source of 100 cm 2, 
CS : Guide value for surface contamination (Annex 3  of the Radiation 
Protection Ordinance).  
4.3 The surface emission response of a device for a giv en nuclide is obtained 
based on the response of selec ted base nuclides. As the reference area, 
100 cm 2 (Annex 3 of the Radiation Protection Ordinance) is to be used. The 
following table lists these base nuclides for diffe rent radiation types. 
 
Nuclide  Half-life  Energy range of α-radiation  
241 Am 432.2 a 5390 - 5490 keV 
 
Nuclide  Half-life  Average energy of β-radiation  
40 - 70 keV  70 - 140 keV  140-400 keV  > 400 keV 
14 C 5,730 a 50 keV    
99 Tc  2.11 · 10 5 a  85 keV   
36 Cl  3.01 · 10 5 a   250 keV  
90 Sr/ 90 Y 28.78 a   190 keV 940 keV 
 
Nuclide a)  Half-life  Energy of γ-radiation  
5 - 15 keV 15 - 90 keV  90-300 keV  > 300 keV 
55 Fe 2.73 a 6 keV    
129 I 1.57 · 10 7 a  32 keV   
57 Co  0.744 a   124 keV  
137 Cs  30.2 a    662 keV 
60 Co 5.27 a    940 keV Ordinance AS 2012 
15 a) Production of suitable sources requires filters for shielding the beta radiation 7 
 
4.4 The selection of the nuclides to be used in the ver ification is dependent on 
the radioactive nuclides which the device is intend ed to mea sure.  
4.5 The reference sources used in the v erification must conform to international 
standards 8,9,10 . In case of deviation from these standards, it is necessary to 
ensure that the deviation does not impact the resul t of the verification. If the 
verification is performed in a test laboratory, the  mea surements are made 
under the usual conditions in laboratories. The bac kground must correspond 
to that of the natural radiation.  
4.6 The distance between the source and the detector wi ndow is equal to 5 mm 
unless a different distance is specified in the op erating instructions.  
5 Validity of the verification 
 The verification is valid for a period of three yea rs. METAS may lengthen or 
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instru ments used 
allow or require such treatment.  
 
  
7 ISO 8769:2010, Reference sources -- Verification o f surface contamination monitors -- 
Alpha-, beta- and photon emitters. 
8 ISO 7503-1:1988 Teil 1 ISO 7503-3:1988: Evaluation  of surface contamination  
9 ISO 8769:2010: Reference sources for the verificat ion of surface contamination monitors  
10  IEC 60325ed3.0 (2002-06): Alpha, beta and alpha/be ta (beta energy > 60 keV) 
contamination meters and monitors  Ordinance AS 2012 
16 Annex 4 
(Art. 10–12) 
Dose calibrators 
1 Construction, metrological characteristics 
1.1 The construction and metrological characteristics o f the dose calibrators 
must conform to the state of the art and the intended application. The dose 
calibrators must display the activity in the legall y mandated units, i.e. in 
Becquerel (Bq).  
1.2 For the verification of the devices, technical specifications, operating i n- 
structions and the following additional device docu mentation must be avai l- 
able: 
– Results of the last semi- annual check of the linearity and reproducibility 
(not required for new acquisitions); 
– Results of the last verification and/or the earlier  comparison measurements 
(not required for new acquisitions); 
– List of all nuclides used in practice and for the verification, with the n u- 
clide -specific calibration factors to be specified by the  manufacturer.  
1.3 The device documentation must clearly show that the  dose calibrator is 
suitable for meas uring the radionuclides with which it is to be veri fied and 
for which it is used.  
1.4 A durable, closed test source for measuring the  stability of the dose calibr a- 
tor must be included with the dose calibrator, e.g.  caesium- 137. The source’s 
activity must be sufficiently high in order to achieve adequate m easurement 
stability in accordance with Point 2.4. In general,  activity of at least 4 MBq 
is required for this purpose.  
2 Verification 
2.1  The dose calibrator must be verified at least once every three y ears.  
2.2  The verification is performed at the dose calibrato r’s location.  
2.3 The verification can be performed only if the m easurement uncer tainty 
ensuing from the stability of the measurement is le ss than 3% at a conf i- 
dence level of 95%.  
2.4 The avai lable test source is evaluated and the associated m easured value is 
recorded in the verification certificate.  
2.5 When verifying the dose calibrator for gamma em itters and beta emit ters 
with a significant gamma component, the verificatio n error limits are ± 10%.  
When verifying the dose calibrator for beta emitter s without a significant 
gamma component in accordance with Point 4.3, the v erification error limits 
are ± 20%.  
2.6  The nuclear medicine laboratory and the FOPH shall be promptly informed Ordinance AS 2012 
17 by METAS or the responsible verification centre if the dose calibrator no 
longer satisfies the verification requirements.  
3 Error limits at inspections 
 If, during an official inspection outside of the v erification, the device’s 
measurement error is greater than the verification error limit, the verification 
shall cease to be valid.  
4 Verification procedure 
4.1  The activity is the reference quantity for the dose  calibrator.  
4.2  The verification is performed using radioactive sou rces in glass vials.  
4.3 When ve rifying the dose calibrator for gamma emitters and beta emitters 
with a significant gamma component, the three nucli des cobalt-57, caesium-
137 and cobalt-60 are used. 
If the dose calibrator is also used by the nuclear medicine laboratory for 
measuring beta emitters without a significant gamma component, inc luding 
especially phosphorus-32, strontium-89, yttrium-90 and erbium- 169, a 
strontium-90 source in which the two nuclides stron tium-90 and yttrium- 90 
are in decay equilibrium is used additionally for t he verification.  
4.4 During the verification, the influence due to t he difference be tween the vial 
type used for the verification and that which is no rmally used in the labora- 
tory is checked.  
4.5 In order to stipulate the reference values for the constancy tests and to check 
the nuclide- specific calibration factors, the dose calibrator i s tested using the 
durable test source in the nuclide settings that ar e used (background count- 
ing rate and yield).  
5 Validity of the verification 
5.1 The verification is va lid for a period of one year. METAS may lengthen or  
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instru ments used 
allow or require such treatment.  
5.2 Performance of a comparison measurement extends  the validity of the veri- 
fication for another year, but with a maximum limit  of up to three years from 
the verification date. This applies also if the dos e calibrator is used by the 
nuclear medicine laboratory for measuring beta emit ters without a signifi- 
cant gamma component and if the comparison measurem ent is performed 
using a gamma emitter or a beta emitter with a sign ificant gamma compo- 
nent.  
6 Comparison measurement 
6.1 The comparison measurement is organised by the veri fication centre. The 
nuclear medicine laboratory’s personnel are respons ible for performing the 
measurements using the dose calibrator under test.  Ordinance AS 2012 
18 6.2 The nuclear medicine laboratory must follow the  verification centre’s i n- 
structions for the comparison me asurements.  
6.3 Unless something else is required by the FOPH, the comparison measur e- 
ments are generally performed using the nuclides te chnetium-99m or iodine -
131. When selecting the nuclide, it is recommended to alternate between 
these two choices.  
6.4  The activity is the reference quantity for the dose  calibrator.  
6.5 The nuclear medicine laboratory may choose between the following two 
procedures: 
– Type A: The verification centre sends a source who se activity it has mea s- 
ured to the nuclear medicine laboratory. (Point 6.5 .1) 
– Type B: The nuclear medicine laboratory sends a sou rce whose activity it 
has determined using the dose calibrator under test  to the verifica tion centre. 
(Point 6.5.2)  
6.5.1 Procedure for the comparison measurement, typ e A 
a) The nuclear medicine laboratory registers for a compari son measurement 
of type A with the responsible verification centre.  
b) The nuclear medicine laboratory is provided with  a source along with 
instructions for performing the comparison measurem ent and a form for 
reporting the test results. 
c) In order to be able to measure the influence due  to the difference between 
the vial type used for the comparison measurement a nd that which is no r- 
mally used in the laboratory, the nuclear medicine lab oratory receives an 
empty vial from the verification centre which corre sponds to the vial which 
is used during the comparison measurement. 
d) The nuclear medicine laboratory is informed of t he value for the activity 
of the provided source as measured by the verificat ion centre after the labo r- 
atory reports its result (to be specified in Bq). 
e) The verification centre sends a certificate to t he nuclear medicine labor a- 
tory.  
6.5.2 Procedure for the comparison measurement, typ e B 
a) The nuclear medicine laboratory registers for a comparison measurement 
of type B with the responsible verification centre.   
b) The nuclear medicine laboratory is provided with  two vials and the pac k- 
aging to be used for transport along with instructi ons for performing the 
comparison measurement and a form for reporting the  test results. 
c) The verification centre determines the upper and  lower limits for the 
source’s activity, taking into account the postal t ransport conditions. 
d) The nuclear medicine laboratory fills one of the  vials with the appropria te 
radioactive solution and determines the activity of  this source in Bq.  Ordinance AS 2012 
19 e) The second vial can be used to measure the influ ence due to the difference 
between the vial type used in the comparison measur ement and that which is 
normally used in the laboratory. 
f) The nuclear medicine laboratory sends the source  along with the test 
results back to the verification centre. 
g) The verification centre measures the activity of  this source. 
h) The verification centre sends a certificate to t he nuclear medicine labora- 
tory.  
6.6 In order for the comparison measurement to be judge d as being successful, 
the difference between the activity measured at the  verification centre and 
that measured using the dose calibrator under test for the source used in the 
comparison measurement must lie within the followin g maximum range: 
± 10% for a comparison measurement with a gamma emi tter or a beta emit- 
ter with a significant gamma component; 
± 20% for a comparison measurement with a beta emit ter without a signifi- 
cant gamma component . 
6.7 If the comparison measurement is unsuccessful, the nuclear medicine labora- 
tory and the FOPH are promptly informed about the u nsatisfactory result.  
 Ordinance AS 2012 
20 Annex 5 
(Art. 13–15) 
Radiation protection measuring instruments for exte rnal radia- 
tion 
1 Construction, metrological characteristics 
 The construction and metrological characteristics of the devices must con- 
form to the state of the art 11  and the intended application. The devices must 
display the dose or the dose rate in the legally ma ndated units.  
2 Verification 
2.1 For each verification, the devices must include  operating instruc tions with 
technical specifications.  
2.2 A check of the device’s correct operation (e.g. wit h test sources) is made at 
regular intervals by the person required to operate  the d evice. This check 
must be documented accordingly. The corresponding t est procedures (time 
intervals, criteria) must be approved by the respon sible supervi sory body. 
The test sources used in these checks are evaluated  on the occa sion of the 
verification and the measured values are recorded i n the verification certifi- 
cate. 
For devices used at a fixed location, such test sou rces must be available for 
the regular functional checks.  
2.3 If possible, the verification covers the device ’s entire measurement range, 
but at least the measurement ranges necessary for t he intended usage.  
2.4  The verification error limits are equal to ± 20%.  
3 Error limits at inspections  
 If, during an official inspection outside of the v erification, the device’s 
measurement error is greater than the verification error limit, the veri fication 
shall cease to be valid.  
4 Verification procedure 
4.1 The reference quantities for dose equivalent measur ing instruments for 
external radiation 12 ,13 ,14  are as follows:  
  
11  The following standards issued by the Internationa l Electrotechnical Commission (IEC) 
can be used as guidelines: 
-IEC 60532 ed3.0 (2010-08) Radiation protection ins trumentation - Installed dose ratemeters, 
warning assemblies and monitors – X and Gamma radia tion of energy between 50 keV 
and 7 MeV;  
- IEC 60846 (2009-04) Ambient and/or directional do se equivalent (rate) meters and/or 
monitors for beta, X and gamma radiation; 
- IEC 61005 ed2.0 (2003-02) Neutron ambient dose eq uivalent (rate) meters 
- IEC 61322 ed1.0 (1994-12) Installed dose equivale nt rate meters, warning assemblies and 
monitors for neutron radiation of energy from therm al to 15 MeV;  Ordinance AS 2012 
21 4.1.1 The ambient dose equi valent H*(10) at the point of interest in the actua l 
radiation field is the dose equivalent which would be generated in the asso- 
ciated oriented and expanded radiation field at a d epth of 10 mm on the 
radius of the ICRU sphere centred on this point whi ch is oriented opposite to 
the direction of incident radiation.  
4.1.2 The directional dose equivalent H'(0.07) at the poi nt of interest in the actual 
radiation field is the dose equivalent which would be generated in the asso- 
ciated expanded radiation field at a depth of 0.07 mm on a specified radius 
of the ICRU sphere.  
4.2 The reference quantities under verification con ditions are stipulat ed by 
METAS or the responsible verification centre.  
4.3 The radiation fields to be used in the verifica tion are determined by the 
radiation type and the measurand for which the devi ce is intended.  
4.4 In general, only one reference quantity is relevant  for a specific radiation; 
the radiations used in the verification and the cor responding reference quan- 
tities are listed in the following table: 
 
Radiation type  Reference quantity  Verification with  
X-ray, γ-radiation  H*(10)  Caesium -137  
Electrons  H'(0.07)  Strontium -90  
Neutrons  H*(10)  Americium -241 / Bery llium  
 
4.5 The irradiation conditions must conform to the ISO standards for reference 
radiation fields 15,16,17 . In case of deviation from these standards, it is neces- 
sary to ensure that the deviation does not impact t he result of the verifica- 
tion. The measurements are performed under the usua l conditions in a labor- 
atory; if necessary, the results are corrected to s tandard conditions for 
pressure and te mperature.  
4.6 Upon special request by the applicant, the veri fication may also be per- 
formed using radiation that differs from that named  in Point 4.4 but is better 
  
12  Determination of Dose Equivalents Resulting from E xternal Radiation Sources. ICRU 
Report 39. International Commission on Radiation Un its and Measurements, Bethesda, 
Maryland (1985). 
13  Determination of Dose Equivalents from External Ra diation Sources - Part 2. ICRU 
Report 43. International Commission on Radiation Un its and Measurements, Bethesda, 
Maryland (1988). 
14  Measurements of Dose Equivalents from External Pho ton and Electron Radiations. ICRU 
Report 47. International Commission on Radiation Un its and Measurements, Bethesda, 
Maryland (1992). 
15  ISO 4037-1:1996, ISO 4037-2:1997, ISO 4037-3:1999 X and gamma reference radiation 
for calibrating dosemeters and doserate meters and for determining their response as a 
function of photon energy  
16  ISO 6980-2:2004, Reference beta-particle radiation  -- Part 2: Calibration fundamentals 
related to basic quantities characterizing the radi ation field. 
17  ISO 8529-2:2000, Neutron Reference Radiations -- C alibration fundamentals of radiation 
protection devices related to the basic quantities characterizing the radiation field  Ordinance AS 2012 
22 suited to the application.  
5 Validity of the verification 
 The verification is valid for a period of three years. METAS may lengthen or 
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instru ments used 
allow or require such treatment.  
 Ordinance AS 2012 
23 Annex 6 
(Art. 18) 
Well-type ionisation chamber systems for Ir-192 HDR  brachy- 
therapy 
1 Construction, metrological characteristics 
1.1 Each system consists of a well- type ionisation chamber, an electrometer and 
an associated durable, closed test source. The cons truction and metro logical 
characteristics of the systems must conform to the state of the art and the 
intended application. They must display the source strength in the unit of air 
kerma strength ( µGy m 2 h-1).  
1.2 The test source’s activity must be sufficiently  high in order to achieve ade- 
quate measurement stability in accordance with Poin t 2.7.  
2 Verification 
2.1 For the verification, the systems must include operating instruc tions with 
technical specifications.  
2.2 During the verification, the system is checked on-site for correct operation 
and calibrated by means of a comparison with the re ference system belong- 
ing to METAS or the responsible verification centre , using an Ir -192 source.  
2.3 The system is approved for use if it can be calibra ted with a relative total 
me asurement uncertainty within ± 3% at a confidence l evel of 95%.  
3 Error limits at inspections 
3.1 The system’s stability must be checked at least qua rterly by performing a 
constancy test with the aid of the test source (con trol display) and the Ir- 192 
so urce.  
3.2 During constancy testing of well- type ionisation chambers which are open to 
the atmosphere, air density correction must be perf ormed for accuracy of at 
least ± 0.3% (confidence level: 95%) using a tracea bly calibrated thermome- 
ter and barometer. During testing of this sort, at least the following  data must 
be recorded in writing: 
a. Date of test, initials of person who performs it ; 
b. Identification of the electrometer, chamber, ada pter, test source and Ir-
192 source; 
c. Control display, display c orresponding to residual current (including 
leakage current) before and after the control curre nt measurement along 
with temperature and air pressure; 
d. Control display corrected for air density (to To = 293.15 K, po = 
1013.25 hPa) as well as the control display converted to the date of the 
test and specified in the verification certificate.  
3.3  During the constancy test, the control display is a llowed a maximum devi a- Ordinance AS 2012 
24 tion of 0.5% from the value recorded in the verific ation certificate and 
converted to the date of the test; otherwise, the verification shall  cease to be 
valid.  
3.4 The applicant and the FOPH shall be promptly inform ed by the verification 
centre if the well-type ionisation chamber system f or Ir-192 HDR brachy- 
therapy no longer satisfies the ve rification requir ements.  
4 Validity of the verification 
 The verification is valid for a period of four year s. METAS may lengthen or 
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instru ments used 
allow or require such treatment.  
 Ordinance AS 2012 
25 Annex 7 
(Art. 19–21) 
Diagnostic dosimeters and measuring instruments for  checking 
X-ray diagnostic equipment 
1 Construction, metrological characteristics 
 The construction and metrological characteristics of the devices must con- 
form to the state of the art and the intended appli cation. This condition is 
fulfilled in particular if the devices conform to t he requirements in the Ordi- 
nance on Medical Devices of 17 October 2001 18 . 
2 Verification 
2.1 For each verification, the devices must include  operating instruc tions with 
technical specifications.  
2.2 During the verification, a check is made whether th e measurement results for 
a specific value of the measurand, or the optical d ensity levels gene rated 
with the sensitometer to be tested, lie within the specified verification error 
limits.  
2.3 The test sources to be used during the regular checks of the diagnostic do- 
simeters are evaluated during each verification and  the values that are meas- 
ured ar e recorded in the verification certificates.  
2.4  Verification scope:  
2.4.1 Diagnostic dosimeters, kV meters, mAs meters, expos ure time meters and 
densitometers: If possible, the verification covers  the device’s entire meas- 
urement range, but at least the measurement ranges necessary for the intend- 
ed usage.  
2.4.2 Sensitometers: During the verification, all of the levels of the grey scale that 
is produced are measured.  
2.4.3 Photometers/luxmeters: During the verificatio n, reference points that corre- 
spond to the recommended values for the illuminatio n level of the light-
beam localiser, or for the luminance of a negatosco pe, are checked.  
2.5  The verification error limits for the different dev ice types are as follows:  
2.5.1  Diagnostic dosimeters: ± 10%  
2.5. 2 Kilovoltmeters: ± 3%  
2.5.3  mAs meters: ± 5%  
2.5.4 Exposure time meters:  
± 1 ms for irradiation times up to 20 ms 
± 5% for irradiation times greater than 20 ms  
  
18  SR 812.213 Ordinance AS 2012 
26 2.5.5 Sensitometers:  
± 0.05 for optical density D ≤ 1 
± 0.1 for optical density D > 1  
2.5.6 Densitometers:  
± 0.025 for optical density D < 1 
± 2.5% for optical density D ≥ 1  
2.5.7  Photometers/luxmeters: ± 10%  
3 Error limits at inspections  
 If, during an official inspection outside of the v erification, the device’s 
measurement error is gre ater than the verification error limit, the verific ation 
shall cease to be valid.  
4 Verification procedure 
4.1 For the verification of diagnostic dosimeters, the reference meas urands are 
as follows: 
- Air kerma for devices which measure the dose; 
- Produ ct (air kerma) x (irradiated area) in a defined pla ne for devices 
which measure the dose area product; 
- Air kerma integrated over the length of the detecto r for devices which 
measure the dose length product.  
4.1.1 The X-ray radiation used to verify diagn ostic dosimeters exhibits the same 
characteristics in terms of energy and time as the radiation that is used 
normally in diagnostic radiology. The reference qua ntities under verifi cation 
conditions are stipulated by METAS or the responsib le verification ce ntre.  
4.1.2 Diagnostic dosimeters are verified for radiat ion qualities that corre spond to 
their application area. A verification can be perfo rmed for the following 
qualities: 
Conventional diagnostic radiology (X-ray tube with tungsten anode): 
 
Incident ra diation, series RQR 19  
Identifier  Tube voltage (kV) (approxi- 
mation, HF generator)  Total filtration 
(mm Al)  HVL (mm Al) 
(half-value layer thickness)  
RQR 3 
RQR 5 
RQR 7 
RQR 9 
RQR 10  50 
70 
90 
120 
150  2.5 
2.5 
2.5 
2.5 
2.5  1.5 
2.5 
3.3 
4.5 
5.7  
  
19  IEC 61267 ed2.0 (2005-11), Medical diagnostic X-ra y equipment - Radiation conditions 
for use in the determination of characteristics Ordinance AS 2012 
27 Radiation behind a patient -equivalent filter, series RQA 20  
Identifier  Tube voltage (kV) (approxi- 
mation, HF generator)  Total filtration 
(mm Al)  HVL (mm Al) 
(half-value layer thickness)  
RQA 3 
RQA 5 
RQA 7 
RQA 9 
RQA 10  50 
70 
90 
120 
150  12.5 
23.5 
32.5 
42.5 
47.5  4.0 
7.1 
9.1 
11.5 
12.8  
    
Here, RQR 5 and RQA 5 are used in the verification as reference beam 
qualities. 
Mammography (X-ray tube with molybdenum anode): 
Incident radiation, reference quality 21  
Identifier  Tube voltage (kV)  Total filtration  
RQN -M 28  0.03 mm Mo  
Radiation behind a patient-equivalent filter 22  
 
Identifier  Tube voltage (kV)  Total filtration  
-----  28  0.03 mm Mo + 2.0 mm Al  
 
Computer tomography (X-ray tube with tungsten anode ): 
Incident radiation, reference quality 23  
Identifier  Tube voltage (kV)  Total filtrat ion  
-----  120  2.5 mm Al  
Radiation behind a patient -equivalent filter 24  
Identifier  Tube voltage (kV)  Total filtration  
-----  120  23.5 mm Al  
 
4.1.3  The conditions during a verification must conform t o the IEC standard 25  for 
  
20  IEC 61267 ed2.0 (2005-11), Medical diagnostic X-ra y equipment - Radiation conditions 
for use in the determination of characteristics 
21  IEC 61267 ed2.0 (2005-11), Medical diagnostic X-ra y equipment - Radiation conditions 
for use in the determination of characteristics 
22  IEC 61674 ed1.0 (1997-10), Medical electrical equi pment - Dosimeters with ionization 
chambers and/or semi-conductor detectors as used in  X-ray diagnostic imaging  
23  IEC 61267 ed2.0 (2005-11), Medical diagnostic X-ra y equipment - Radiation conditions 
for use in the determination of characteristics  
24  IEC 61674 ed1.0 (1997-10), Medical electrical equi pment - Dosimeters with ionization 
chambers and/or semi-conductor detectors as used in  X-ray diagnostic imaging Ordinance AS 2012 
28 dose measuring instruments and dose length product measuring instruments 
and to the IEC standard 26  for dose area product measuring instruments. The 
measurements are performed under the usual conditio ns in laboratories; if 
necessary, the results are corrected to standard co nditions for pr essure and 
temperature.  
4.1.4 Upon special request by the applicant, the ve rification may also be per- 
formed using radiation that differs from that named  in Point 4.1.2 but is 
better suited to the application.  
4.2 The X-ray radiation used to verify kilovo ltmeters must exhibit the same 
characteristics as the radiation that is used norma lly in diagnostic radiology. 
METAS or the responsible verification centre stipul ates the radiation quality 
and the reference quantity under verification condi tions.  
 Kilovoltmeters are verified for the following radi ation qualities:  
Conventional diagnostic radiology (X-ray tube with tungsten anode): 
Incident radiation, series RQR 27  
Identifier  Tube voltage (kV) (approxi- 
mation, HF generator)  Total filtration 
(mm Al)  HVL (mm Al) 
(half-value layer thickness)  
RQR 5 
RQR 7 
RQR 9  70 
90 
120  2.5 
2.5 
2.5  2.5 
3.3 
4.5  
Mammography (X-ray tube with molybdenum anode): 
Identifier  Tube voltage (kV)  Total filtration  
RQN -M 28  0.03 mm Mo  
 
4.3 During verification of mAs meters, the charge i s measured with the refer- 
ence device in series.  
4.4 During verification of exposure time meters (in vasive and non- invasive), the 
comparison is performed using an invasive reference  device.  
4.5 During verification of sensitometers, the two g rey scales, which are generat- 
ed on the same X-ray film through exposure – one by  the refer ence device 
and the other by the device to be verified – are compared dens itometrically.  
4.6  During verification of densitometers, a calibrated grey scale is used.  
4.7 During verif ication of photometers/luxmeters, a comparison with  a reference 
device is performed; the centre of a negatoscope’s surface is used as the light 
source.  
  
25  IEC 61674 ed1.0 (1997-10), Medical electrical equi pment - Dosimeters with ionization 
chambers and/or semi-conductor detectors as used in  X-ray diagnostic imaging 
26  IEC 60580 ed2.0 (2000-01) Medical electrical equip ment - Dose area product meters  
27  IEC 61267 ed2.0 (2005-11), Medical diagnostic X-ra y equipment - Radiation conditions 
for use in the determination of characteristics  Ordinance AS 2012 
29 5 Validity of the verification 
 The verification is valid for a period of three ye ars. METAS may lengt hen or 
shorten the validity periods for individual types m ade by certain manufac- 
turers if the metrological characteristics of the m easuring instru ments used 
allow or require such treatment.  
 Ordinance AS 2012 
30 Annex 8 
(Art. 22–24) 
Radon measuring instruments 
1 Construction, metrological characteristics 
 Radon measuring instruments must fulfil the followi ng requirements in 
particular:  
1.1  Measurand: Radon activity concentration in Bq/m 3; 
1.2 Lowest radon activity concentration that must b e measurable: 10 Bq/m 3 for 
1 hour m easurement interval;  
1.3  Measurement range: Up to 100,000 Bq/m 3; 
1.4  Linearity: Error < 10% between 10 Bq/m 3 and 10,000 Bq/m 3; 
1.5  Reproducibility: Standard deviation s ≤ 5%.  
2 Procedure for placing on the market 
2.1 Anyone submitting radon measuring instruments f or initial verifi cation must 
include technical specifications, operating instruc tions and the associated 
program for eval uation of the measurement data on a suitable data s torage 
medium.  
2.2 The reference value used by METAS or the respon sible verifica tion centre 
must lie within the range of values measured by the  radon measuring in- 
struments in residential and work spaces.  
2.3  The verification error limits for radon measuring i nstruments are ± 20%.  
3 Procedure to preserve measurement stability 
3.1 In accordance with Annex 7 Point 1 of the Measu ring Instruments Ordi- 
nance 28 , radon measuring instruments must be reverified ev e ry four years by 
METAS or a verification centre. METAS may lengthen or shorten the va- 
lidity periods for individual types made by certain  manufac turers if the 
metrological characteristics of the measuring instr uments used allow or 
require such treatment. 
 
3.2  The requirements in Point 2 apply to the reverifica tion.  
4 Error limits at inspections 
 If, during an official inspection outside of the ve rification, the device’s 
measurement error is greater than the verification erro r limit, the verification 
shall  cease to be valid.  
  
28  SR 941.210 Ordinance AS 2012 
31 Annex 9 
(Art. 25–27) 
Specific requirements for radon dosimeters 
1 Construction, metrological characteristics 
 Radon dosimeters must fulfil the following requirem ents in particular:  
1.1  Measurand: Radon exposure in kBq h/m 3; 
1.2  Inte gration time: > 1 month;  
1.3  Lowest exposure that must be measurable: 50 kBq h/m3; 
1.4  Measurement range: Up to 15,000 kBq h/m 3; 
1.5  Linearity: Error < 15% between 50 kBq h/m 3 and 10,000 kBq h/m 3; 
1.6  Reproducibility: Standar d deviation s ≤ 15%.   Ordinance AS 2012 
32