NOMEX Multimeter
Contents
1. The NOMEX multimeter delivery comprises NOMEX software 2m USB cable 5 m USB active extension cable calibration certificate user manual compact transport case 2 PTW NOMEX Fig 1 NOMEX multimeter L981815 Optionally available NOMEX multimeter holder for use with a tripod or for fixing via hook and loop tape e g at dental panoramic units NOMEX cassette adapter for use within the image receiver plane Mobile PC Fig 2 NOMEX multimeter holder T20016 a Fig 3 NOMEX cassette adapter T2001 7 gt Comprehensive NOMEX calibration The NOMEX multimeter is calibrated within the radiography fluoroscopy dental CT and mammography range according to the radiation qualities given by the IEC 61267 2 In mammography the NOMEX comes calibrated ready to be used for all common radiation qualities Mo 25umRh Mo 0 5mmAl W 0 7mmAl W 60umMRh W 60umAg and Rh 30umRh Moreover a compression paddle correction factor is provided for each quality The NOMEX multimeter factory calibration comprises the calibration of air kerma and air kerma rate tractable to the PTB tube voltage measured by means of a high voltage divider time total filtration and half value layer Due to the worldwide well known reliability reproducibility and long term Stability of PTW devices a recalibration is recommended only every 2 years 3 6 gt Quick measurement setup The smart NOMEX multimeter2. Time 0 000 s aes Half Value Layer 0 00 mmal Total Filtration 0 0 mm Al IM Dose Rate Dose per Pulse 0 000 sy Frequency 0 0 Hz Pulses 0 Fig 10 Modifiable display and parameter order Statistic calculations mean value standard deviation coefficient of variation by means of marking the results of interest Dose Rate Dose Mean kp Exposure Time Half Value 2012 04 04 14 22 36 584 0 mR s 250 8 mR 27 8 kV 429 5 ms 0 542 mr 2012 04 04 14 27 14 868 9 mR s 373 6 mR aE E a A 430 0 ms 0 585 mr 2012 04 04 14 30 03 605 5 mR s 260 1 mR 28 8 kV 429 5 ms 0 559 mr 2012 04 04 14 51 41 837 6 mR s 360 2mR 324k 430 0 ms 0 601 mr 2012 04 04 14 59 09 161 0 mR s 581 7 mR 29 8 kY 3 614 s 0 541 mr gt 2012 04 04 15 01 07 245 6 mR s 886 2mR 346kV 3 608 s 0 627 mr Mean value 33 367E 00 kV 2 8 Standard deviation 917 73E 03 kV Coefficient of variation 0 028 Adjustable timer functions measurement start and stop delays Adjustable waveform sampling frequency starting from 3 seconds with full 2 3 kHz up to 60 seconds with 100 Hz 5 6 Possibility to fade in a start stop button if a manually triggered measurement is required Value presentation in technical notation or with unit optionally in Gray or Roentgen Data export as XML or CSV file for subsequent processing in Excel or protocol printing as PDF file Zooming of a waveform section r ii 100 TEES Zoom graphic section seco A DOAI bah pp
3. NOMEX Multimeter True Precision PTW CE marked class llb certified device Compliance with IEC 61674 accuracy 5 Recommended recalibration every 2 years gt Fully automatic dose and kV ranging Fully automatic TF compensation kVp meas for all appl ranges amp qualities PPV calc acc to the IEC 61676 algorithm v Commercial Note D909 199 01 00 P VV According to the European Medical Directive MDD an accessory for X ray equipment is also a medical device Meanwhile users know about their legal responsibilities and check certification status of medical device accessories Some devices show outliers for dose measurements exceeding 5 especially at the end of the measuring ranges Acc to IEC 61674 the relative uncertainty for air kerma measurements shall not exceed 5 within the complete measuring ranges from 23 35 kV and 40 150 kV NOMEX fulfils and even exceeds the requirement RAD FLU typically 1 5 and MAM 2 5 Some devices must be send in for recalibration every year Requiring a recalibration every year points at a bad long term stability The energy response sensitivity of the device changes with the result that the calibration factors are not valid and therefore the measuring results are not reliable any more Moreover requiring a recalibration every is a non negligible cost factor PTW devices are famous for reliability reproducibility and their outstanding long term stability Recalibra
4. acy with respect to the parameters dose and dose rate is outstanding and exceeds the requirements of IEC 61674 stated with 5 1 Dose accuracy The dose accuracy within the complete conventional measuring range from 40 150 kV is typically 1 5 and within the mammography range from 23 35 kV 2 5 kV accuracy kV accuracy within the conventional measuring range is typically 0 75 or 0 5 kV Additionally PPV measurements in accordance with the algorithm of IEC 61676 3 are possible gt Summary International standards and regulations for acceptance and quality control tests of diagnostic X ray units require the check of a variety of parameters NOMEX was designed to measure and to evaluate different quantities in one single operation making no compromise with respect to the measuring accuracy le l PIW NOMEX Multimeter pp Increasing QC efficiency in diagnostic radiology departments NOMEX as an all round acceptance and service test device is covering all applications and the complete range of measuring tasks fast easy and truly precise References 1 IEC 61674 International Electrotechnical Commission Medical electrical equipment Dosemeters with ionization chambers and or semiconductor detectors as used in X ray diagnostic imaging 2 IEC 61276 International Electrotechnical Commission Medical Diagnostic X ray Equipment Radiation conditions for use in the
5. can be directly connected via USB cable to a tablet netbook or PC running the NOMEX software No additional and costly accessories e g a sperate display are required to operate the system NOMEX can be positioned within the central beam independently of any consideration of the tube axis alignment as the ergonomic CE marked class llb certified meter functions independent of orientation Due to its weight and functional affixed rubber pads NOMEX will not shift after being placed on the patient couch For vertical measurements such as on a wall stand the multimeter can easily be attached using the optional NOMEX multimeter holder gt Automatic NOMEX adjustment NOMEX sets up itself automatically The following implemented features guarantee a trouble free workflow Auto start stop Measurements start and stop automatically after detection of radiation Auto dose ranging Dose ranges are set fully automatically so that annoying and time consuming double exposures can be avoided Auto kV ranging kV ranges are set fully automatically There is no need to adjust the meter to the correct kV range before the measurement Auto total filtration compensation Within the RAD FLU DENT CT range the adjustment of the X ray tube filtration is not necessary based on the implemented total filtration compensation up to 40 mm aluminium Auto HVL detection For all applications even for mammography and for all MAM radiatio
6. determination of characteristics 3 IEC 61676 International Electrotechnical Commission Medical electrical equipment Dosimetric instruments used for the non invasive measurement of X ray tube voltage in diagnostic radiology 6 6
7. e of a measuring problem The user always knows about the measurement quality and what to do in case of an problem NOMEX is equipped with a modern boot loader technology Downloading the latest firmware version via internet within seconds reduces unnecessary delivery costs and working off times due to long delivery and redelivery periods to a maximum For corrections and or additional information please contact marketing ptw de All specifications subject to change without notice Part of D909 199 01 00 2012 05 2 6 PTW Commercial Note D909 199 01 00 NOMEX Multimeter gt About the NOMEX multimeter The NOMEX multimeter is a non invasive miniaturized multi parameter measuring device combining semi conductor detectors and electronics according to IEC 61674 1 With the NOMEX multimeter measurements of the dose dose rate dose per pulse pulses exposure time tube voltage maximum mean and practical peak half value layer HVL and total filtration TF are possible simultaneously in just one single exposure Additionally the kV and dose rate waveform is logged gt Intended use of NOMEX multimeter The NOMEX multimeter is used for quality assurance and quality control measurements on medical imaging X ray installations Hence the NOMEX multimeter can be used during acceptance tests or routine constancy checks of radiographic fluoroscopic dental CT and mammography X ray units gt NOMEX multimeter components
8. g in Ih D i WI 3 j vW Waveform data export Device settings for each measurement are automatically logged and comments can be attached to each measurement Comment MAM WW 50 um Rh Incl Comp Paddle 23 kW 35 kY 3 s Stop Delay dit comment MAM VV 50 um Ag Incl Comp Paddle 23 kW 35 kY 3 s Stop Delay MAM VV 50 pm Ag Incl Comp Paddle 23 kV 35 kY 3 s Stop Delay Snapshot function of the measuring screen for fast attachment to a protocol Setup menu available in different languages Chinese English French German Italian Japanese Portuguese Russian Spanish RAD FLU DENT Setup Display and Audio g Language Engish B Deutsch il Intro Francais Espanol Italiano amp Beep z Portugu s Audio signal indicating the availability of a new measurement No software licensing allowing unlimited installations on different PCs for no additional cost Sophisticated assistance in case of measuring problems such as dose rate overrange etc The NOMEX software combines intuitive operation and coherent data handling leading to fast reliable and PTW like precise results gt NOMEX True Precision The requirements for the performance of dosemeters and semi conductor detectors as used in X ray diagnostic imaging are given in the international standard IEC 61674 1 those for non invasive measurements of the X ray tube voltage in IEC 61676 3 The NOMEX accur
9. l text error messages Firmware updates via internet possible T Commercial Note D909 199 01 00 D I VV NOMEX detects the HVL for all applications including all common mammography radiation qualities Mo 30umMo Mo 25umRh Mo 0 5mmAl W 0 7mmAl W 60umRh W 60umAg and Rh 30umRh In mammography the NOMEX multimeter comes calibrated ready to be used for all common radiation qualities such as Mo 30umMo Mo 25umRh Mo 0 5mmAl W 0 7mmAl W 60umRh W 60umAg and Rh 30umRRh Moreover a compression paddle correction factor is provided for each quality The NOMEX multimeter fits with 115 mm x 50 mm x 9 mm within the cassette plane Moreover an optional cassette adapter is available for most convenient use within the image receiver plane The NOMEX multimeter can be positioned in RAD FLU DENT and MAM within the central beam independently of the tube axis orientation Time consuming alignments according to the tube axis are absolutely unnecessary Some devices are indicating a measuring result even if it is absolutely wrong It is then up to the user to decide whether the result is reliable poorly or completely wrong PTW knows what responsibility means therefore the NOMEX multimeter has a sophisticated error management which informs the user about the quality of the measuring result Poor measuring accuracies are indicated self evident Additionally NOMEX suggests what to change within the software settings or within the measurement setup in cas
10. n qualities the half value layer HVL is determined Based on these features the NOMEX setup simply comprises the following three steps pe A O J if gt Connect Fig 4 5 USB connection to any tablet netbook or laptop Fig 6 Positioning independent of orientation Fig 7 Functional housing avoids shifting gt evaluate Fig 8 Setup unit and expose Fig 9 Analyze and store data 4 6 gt Time saving amp cost effective workflow Within the NOMEX software only the corresponding application RAD FLU DENT DENT PAN CT or MAM has to be selected Once the application is selected no fine tuning needs to be undertaken before measurement can take place as NOMEX sets up the rest automatically After an exposure the results will be displayed and listed in a data set chart for further analysis Additionally the logged voltage or dose rate waveform for each measurement can be viewed The measured data can be stored printed copied or alternatively exported as a XML or CSV file gt NOMEX software features The customizable parameter display allows viewing of all parameters at a glance or just specific items of interest RAD FLU DENT 40kV 150kV EC ke RAD FLU DENT Dose Rate 40kV 150kV LEC fe RAD FLU DENT Dose PPV 40kV 150kV LC be Dose Rate 0 _000 Gyls Max kVp Half Value Layer Dose 0 000 Gy Mean kVp 0 0 kv Total Filtrati ii Exposure
11. tion of the NOMEX is recommended only every 2 years Some devices require multiple shots before the real measurement can be performed These pre measurements reveal the device s shortcomings in regards to auto ranging Based on the implemented fully automatic ranging multiple exposures for finding the correct dose and or kV range are avoided when using the NOMEX The total filtration TF compensation allows the performance of kV measurements without adjusting the device to the existing tube filtration mm Al The device identifies the filtration and corrects the kV measurement result accordingly NOMEX measures the TF within the complete specified measuring range 40 kV 150 kV without any exception In contrast to other devices which only allow a kVp detection for a subset of selected radiation qualities the NOMEX multimeter offers kVpmax kVpmean and PPV measurements within the complete specified energy range 23 35 kV and 40 150 kV without exception NOMExX provides the kV parameters not only for Mo 30umMo but also as standard for all mammography qualities Mo 25umRh Mo 0 5mmAl W 0 7mmAl W 60umRh W 60umAg and Rh 30umRRh NOMEX calculates the practical peak voltage PPV according to the algorithm described in IEC 61676 NOMEX Multimeter HVL reading for all MAM qualities All MAM qualities included as standard Usability within the image receiver plane Angular independence of rotation orientation Ful
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