R134/2006-A-CZ1-23.01

1 Characteristics of the instrument

Automatic weighing instrument having a load receptor carried out by sensors and aprons that determines the vehicle mass parameters.

2 Main metrological characteristics

$ ^{1} $) In-motion tests (initial verification, subsequent verification, in-service inspection) must cover a speed range of 5 to 20 km/h.

$ ^{2} $) In-motion tests (initial verification, subsequent verification, in-service inspection) must cover a speed range of 120 to 140 km/h.

$ ^{3} $) The temperature range may be extended if datalogger installed in airconditioned cabinet.

4. 3 rows of transverse sensors or 2 rows of transverse sensors combined with 1 row of tilted sensors,

4 rows of transverse sensors or 3 rows of transverse sensors combined with 1 row of tilted sensors.

3 Composition of the instrument - measuring system

• Measurement unit for data collection, digitalization and processing,

• vehicle presence detector (inductive loops or an external detector),

• load (weighing) sensors installed in the road,

• tilted sensors for vehicle position measurement which can be also used for weighing,

• interfaces for auxiliary devices and additional road sensors,

• evaluation unit (computer, external or integrated inside the measurement unit) with installed software and recording equipment.

The system enables integration with additional vehicle identification equipment such as ANPR/LPR cameras, overview cameras, video systems and others. The system also enables integration with additional auxiliary devices and systems such as external vehicle detectors, dimension measurement systems, informative variable message signs, surveillance systems and others.

3.1 Load/Weighing sensors

Piezoelectric load sensors from manufacturer Kistler of type series LINEAS or sensors from manufacturer CAMEA of type series US-PQ are used within the measuring system.

3.2 Measurement unit UC-ZPU - data collection, processing and digitization

• UB-IND - inductive loop input board.

The UC-ZPU unit is of modular design and allows the use of different types of input and output boards and thus the connection of different combinations and types of sensors and devices. The number and type of inputs of this unit is variable.

Basic types of input and output boards:

• UB-DIO - IO signal board.

• During the measurement, the system detects the presence of the vehicle, measures the dynamic forces on the tires as a function of time and calculates the values of the total weight and the load on the axle or group of axles. The data from the measurement unit is processed and evaluated by the installed software.

• UB-PRS - charge input board.

• UB-LCS - strain gauge input board.

The principle of measuring the weight on the quartz crystal sensors is the conversion of the load on the sensor into a charge Q. The area of the generated charge pulse is directly proportional to the measured weight at a given vehicle speed.

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3.3 Software equipment

3.3.1 General software equipment security

The software equipment under metrological control complies with the following general characteristics: a) Access is allowed only to an authorized person using codes (keyword) that are changeable.

a) Access is allowed only to an authorized person using codes (keyword) that are changeable.

b) All interventions of the operator or the superior control system are automatically stored in the memory (intervention/audit log), stating the date and time of the intervention, identification of the authorized person performing the intervention and the type of intervention.

c) When the memory capacity for storing intervention records is exhausted, no stored records are deleted automatically.

d) The relevant intervention records may be retrieved in full.

e) Deletion of intervention records is not permitted to any person other than the authorized person.

f) Downloading software under metrological control is only possible via an appropriate protected interface.

g) The software version identification number is attached to the software and changes in the event of any change in the software.

h) Functions that are performed or initiated via the software interface meet the requirements and conditions of the OIML R134-1 (2006).

3.3.2 Wimer application

The Wimer application is the software performing vehicle identification and separation, speed and weight measurement. The software is divided into two parts. The separate legally relevant part and the remaining legally irrelevant parts of the application which may be subject to changes (updates).

The software is identified as follows: Wimer 2.xxx.081. The first part is a number (2) indicates the main version of the software, the second part consists of three digits (xxx) that identify the legally irrelevant version that may be subject to change and the third part consists of three digits (081) that identify the version of the legally relevant part. Identification of the legally relevant part of the application is shown in the following table:

The software is unambiguously identifiable by the version listed in the header of the GUI window. Any change in the software will result in a change in the version number. The change of the legal part is reflected in the last three digits, while the change of the other parts in the previous three digits.

The system performs checksum checks at startup. The checksums are performed separately on the binary file of the legally relevant part and separately on the binary file of the legally irrelevant parts of the application. Identification of both parts of the application and both checksums are listed in the application GUI.

The state of the installed software instance (main binaries, settings file, the audit log and users) is protected against accidental or intentional changes using a HMAC SHA256 checksum. Any change in the checksums of the legally relevant part or of the legally irrelevant parts of the application is recorded in the intervention records (audit log). Any unauthorized change causes the application to block the measurement operation.

The software can be additionally equipped with an electronic seal in order to prevent changes during the verification validity period. The electronic seal is implemented using a HW security token. If the software cannot find the token, i.e., the token is not present, user login is not possible. The token provides a form of a two-factor authentication.

The software is equipped with measurement result validation. The software measures each passing vehicle and then validates the signal and measurement results. The validation result is a part of the measurement result. Invalid records cannot be used for legally relevant purposes.

3.3.3 VIOLATOR software module

The VIOLATOR software module provides functions needed for creating an electronic output document. The software combines visual data with the measurement results and compiles sequentially numbered electronic documents in a proprietary .offence format. The electronic documents are signed by a private key using the RSA2048 SHA256 method.

The software module also provides a function for exporting the electronic documents in .offence format to the .xml format, which is then signed using the xmldsig RSA2048 SHA256 method and a private key. These exported electronic documents can be moved to the storage and processing location using various interfaces (based on the configuration).

The VIOLATOR software module is hosted by modular hosting application. The hosting application provides interaction with systems for visual identification and additional auxiliary devices and systems. Both the hosting application and the VIOLATOR software module are secured by the Authenticode method (digital signature codesigning by a certificate with a checksum of the signed data using an SHA256 algorithm). The configuration is protected by the HMAC SHA256 hash.

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