R134/2006-A-CZ1-25.03
| OIML Member State Czech Republic | OIML Certificate No. R134/2006-A-CZ1-25.03 |
| Czech Republic | R134/2006-A-CZ1-25.03 |
| OIML CERTIFICATE ISSUED UNDER SCHEME A | |
| OIML Issuing Authority Name: Czech Metrology Institute Address: Okružní 31 638 00 Brno Czech Republic Person responsible: Jan Kalandra | |
| Applicant Name: iWIM S.r.l. Address: Via Kufstein 1 38121 TRENTO (TN) Italy | |
| Manufacturer Name: iWIM S.r.l. Address: Via Kufstein 1 38121 TRENTO (TN) Italy | |
| Identification of the certified type (the detailed characteristics will be defined in the additional pages) Automatic instrument for weighing road vehicles in motion type: iWIM_90_10 BISON_140_10 | |
| Designation of the module (if applicable) | |
| This OIML Certificate attests the conformity of the above identified type (represented by the sample(s) identified in the OIML type evaluation report) with the requirements of the following Recommendation of the International Organization of Legal Metrology (OIML): | |
Edition (year): 2006
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| This OIML Certificate relates only to metrological and technical characteristics of the type of measuring instrument covered by the relevant OIML Recommendation identified above. This OIML Certificate does not bestow any form of legal international approval. | ||
| The conformity was established by the results of tests and examinations provided in the associated reports: Test report No.6012-PT-R0050-25 dated4.12.2025 that includes38 pages. Test report No.6012-PT-R0051-25 dated4.12.2025 that includes41 pages. Test report No.8551-PT-E0038-24 dated25.4.2024 that includes1+28(Test report+annex)pages. Test report No.8551-PT-E0058-24 dated25.4.2024 that includes1+43(Test report+annex)pages. Test report No.6011-PT-SW031-25 dated4.12.2025 that includes3+3(Test report+annex)pages. OIML type evaluation report0511-ER-W107-23 dated4.12.2025 that includes6 pages. | ||
| The technical documentation relating to the identified type is contained in documentation file: 0511-UL-W107-23 OIML Certificate History | ||
| Revision No. | Date | Description of the modification |
| - | 5 December 2025 | Issuing of certificate |
| The OIML Issuing Authority RNDr.Pavel Klenovský Director of Certification Body Date:5 December 2025 | ||
Important note: Apart from the mention of the Certificate's reference number and the name of the OIML Member State in which the Certificate is issued, partial quotation of the Certificate and of the associated OIML type evaluation report(s) is not permitted, although either may be reproduced in full.
1 INSTRUMENT NAME AND DESCRIPTION
iWIM is a weighing instrument designed for determining the total weight (gross vehicle weight) of road vehicles.
1.1 Essential parts
Light sources:
Any light source (standalone or integrated into the interrogator) (SLED/ASE) with following requirements:
Optical power: > 1mW
Band: covering FBG wavelength +/- 2nm
Band flatness: < 6dB
Interrogator:
The spectrometer is used. For more details see documentation folder 0511-UL-W107-23.
PC:
x86-64 or compatible PC, with USB 2.0 or better, 8GB RAM, Linux OS
Power supply:
The interrogator is powered up by the PC USB port.
1.2 Weighing area
The installation site must feature a stable, non-deformable apron (concrete, asphalt, or similar) extending upstream and downstream of the weighing platform, with a length of at least 20 m upstream and 15 m downstream. The plates can be installed in a staggered or in-line arrangement. The surface must be rectilinear and coplanar with the weighing platform. There must be no bumps, steps, or offsets between the road pavement and the load receptor. The longitudinal slope must be negligible in any case less than 4%, while the transverse slope should be minimized to strictly what is needed for drainage.
Installation example multi-lane configuration
Figure 1 example of installation
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1.3 Mechanical design of bending plate
FBG (fiber Bragg grating) optical sensor on the bottom side of bending plate.
Figure 2 sensor installation in the road surface
1.4 Principle of operation
The optical signal is generated by sensors located under the weighing plate and transmitted via optical fiber to a specific optical interrogator. Optional passive optical elements such as circulators, splitters, or attenuators could be used.
The interrogator and the computation PC are housed together in a sealed, tamper-proof box. Inside, legally relevant software processes and calculates the weight data. To ensure the authenticity of the data sent to optional interoperable devices (e.g., remote displays, tablets, printers, or the cloud), the software applies a digital signature to the output. This guarantees data integrity regardless of the transmission channel, making a physical primary display on the datalogger non-mandatory, as it can be effectively replaced by a secure virtual or remote display. Furthermore, thanks to the digital signature applied to metrologically relevant data, extra functionalities (which are not metrologically relevant) can safely operate on the same PC, as the signature guarantees that the critical measurement data remains unaltered and uncompromised.
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Figure 3 Principle of operation
1.5 Block diagram
Figure 4 Block diagram of used devices and its connection
2 MAIN METROLOGICAL CHARACTERISTICS
| Type | iWIM_90_10 | BISON_140_10 |
| Accuracy class for Vehicle mass | 10 | |
| MaxGVW | 1980000kg | 1980000kg(for speed<=100km/h)4500kg(for speed>100km/h) |
| MinGVW | 2000kg | |
| Verification scale intervald | 100kg | |
| Maxaxle | 20000kg | |
| Minaxle | 1000kg | |
| Maximum number of axlesa max | 99 | |
| Operating speed range | 5-100km/h | 5-100km/h(forGVW>4500kg)5-140km/h(forGVW<=4500kg) |
| Load receptor configuration | 2or more bending plates | |
| Temperature range(load receptors) | -30℃-+70℃ | |
| Temperature range(cabinet equipment) | -10℃-+70℃ | |
| Vehicle position detection | automatic(cross) lane detection and identification | |
| Software identification | v2.0SHA-256hash:e6447c408d1e252bb4a9f1ef879c7d5589c48dbe3be65f03d5188470fed249b4 | |
Table 1: iWIM metrological characteristics
When instrument is installed in a region where temperatures in cabinet could be lower than $ - 1 0^{\circ} \mathrm{C} $ , it's prescribed to install heating, alternatively the system stops working. The weighing range for the total vehicle weight (Gross vehicle weight - GVW) is determined as the product of the weighing range of one axle and the maximum number of weighable axles $ \left( \mathrm{A}_{\mathrm{m a x}} \right) $ .
$$ \mathrm {M a x} _ {\mathrm {G V W}} = \mathrm {M a x} _ {\mathrm {a x l e}} * \mathrm {A} _ {\max } $$
- 1.1 Main instrument label
| Manufacturer | iWIM S.r.l. Italy | |
| Type designation | iWIM_90_10 | BISON_140_10 |
| Serial number | #xxx | |
| Maximum transit speed | 250km/h | |
| Direction of weighing | bi-directional | |
| Power supply voltage | 110-240V AC50/60Hz | |
| Temperature range(load receptors) | -30℃-+70℃ | |
| Temperature range(cabinet equipment) | -10℃-+70℃ | |
| Software version | v2.0SHA-256hash:e6447c408d1e252bb4a9f1ef879c7d5589c48dbe3be65f03d5188470fed249b4 | |
| Accuracy class vehicle mass | 10 | |
| Maximum capacity(GVW):Max= | 1980000kg | 1980000kg(for speed<=100km/h)4500kg(for speed>100km/h) |
| Minimum capacity(GVW):Min= | 2000kg | |
| Maximum capacity(axle):Max= | 2000kg | |
| Minimum capacity(axle):Min= | 1000kg | |
| Scale interval:d= | 100kg | |
| Maximum operating speed: $ \nu_{\mathrm{max}} $ | 100km/h | 100km/h(forGVW>4500kg)140km/h(forGVW<=4500kg) |
| Minimum operating speed: $ \nu_{\mathrm{min}} $ | 5km/h | |
| Maximum number of axles per vehicle: $ a_{\mathrm{max}} $ | 99 | |
| Type approval sign in accordance with national regulations | ||
Table 2 example of main label of the weighing instrument
The main label is secured with a verification mark.
3 SOFTWARE
The legally relevant software of the scales and its security meet the requirements of the WELMEC 7.2:2023 software guide.
The legally relevant software is monolithic C++ architecture running on a secure Linux operating system. The integrity of this element is guaranteed by checking its checksum SHA-256 hash.
The core metrological integrity is maintained through a combination of Physical Sealing (tamper-evident labels on the Datalogger Box) and Electronic Sealing (SHA-256 software signatures and blockchain-linked audit trails).
The metrological integrity of each record is guaranteed by digital signing of each record, preventing any data corruption and/or intentional manipulation.
4 VERIFICATION AND SECURING OF THE WEIGHING INSTRUMENT
The metrological tests must be carried out according to national applicable regulations.
4.1 Securing components and verification marks
All hardware components are protected with anti-tamper stickers. Figures 5 a,b,c show the positions of the 6 seals (2 on front screws, 4 on side corners) on the Datalogger Box.
Figures 5 a,b,c example of sealing