Decree No. 70 / 2004 Coll.
Order setting out the requirements for shredding machines and presses
Valid
Effective from 01.03.2004
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70
DECLARATION
of 3 February 2004
laying down requirements for shredding machines and presses
The Ministry of Industry and Trade provides pursuant to Section 27 of Act No. 505 / 1990 Coll., on Metrology, as amended by Act No. 119 / 2000 Coll. and Act No. 137 / 2002 Coll., ("the Act") for the implementation of Sections 6 (2) and 9 (1) of the Act:
This Decree sets out requirements for shredding machines and test presses (hereinafter referred to as "test machines'), the type approval procedure and the procedure for verifying them.
The terminology and test machine requirements, as well as their approval and verification, are set out in the Annex.
This Decree shall take effect on 1 March 2004.
Minister:
Ing. Urban v. r.
Annex to Decree No. 70 / 2004 Coll.
1 TERMINOLOGY
1.1. Tearing machines are test machines for mechanical testing of material for which the test sample of material is loaded with a static acting single axis force during tensile loading.
1.2. Test presses are test machines for mechanical testing of material where the test sample of material is loaded with a static single axis force at pressure loading.
1.3. Verification of the test machine is a procedure to detect its properties. It consists of a general assessment of the test machine and verification of the force measuring system.
1.4. A general assessment of the test machine is the procedure to be carried out before the test machine's measuring system is checked.
1.5. Verification of the test machine is a set of activities which, under the specified conditions, establish the relationship between the values indicated by the test machine force measurement system and the reference values to be determined by an etalon load gauge.
1.6. The measuring device of the test machine force is the sum of the devices used to determine the value of the test force applied to the sample. It consists of a scanning and indicating device. In principle, three basic measuring systems are identified. Mechanical measuring system, hydraulic measuring system and electromechanical measuring system.
1.6.1. The mechanical measuring system operates on a mechanical principle. The force applied to the sample shall be compensated by the force of the spring or by the load-bearing mass placed on the lever of the lever. The indication device is exclusively analogue with a linear, circular or arc scale.
1.6.2. The hydraulic measuring system is based on measuring the oil pressure in the cylinder of the loading system. The indicator device is usually a piston or deformation manometer. This manometer is adapted for the design of the test machine.
1.6.3. The electromechanical measuring system is based on direct measurement of the test force by a tensimetric force sensor or on the measurement of oil pressure in the cylinder of the load system by a tensimetric pressure sensor. The sensor output signal is amplified and converted into a digital form. The indication of the test result can be performed here in many ways. From the output of the power value on an analogue or digital scale in the form of a force value, to the output of the recorder in the form of a voltage dependent diagram on the extension to the complex output of the material on the computer printer with the storage of values in the computer memory.
1.7. The load equipment of the test machine is used to derive the test force applied to the sample. Two basic types of loading equipment are used for test machines. Mechanical and hydraulic loading devices.
1.8. The test machine frame is usually a structure in which the test machine loading system and the reading part of the force measuring system are located.
2 REQUIREMENTS FOR TEST MACHINERY
2.1. METHOLOGICAL REQUIREMENTS
2.1.1 Requirements for test machines
The shredder is divided into four classes according to metrological parameters according to the relative error values given in Table 1.
Table 1 gives the maximum permissible values for the various relative errors of the test machine's measurement power and the relative differentiability of the indicator device, which characterise the range of the test machine according to the class.
The measuring range of the indicator device shall be considered satisfactory if the check was satisfactory at least for the range of force measurements between 20% and 100% of the nominal force of the range concerned.
Table 1. Limits for relative errors of the test machine force measuring device
| Třída stupnice stroje | Maximální dovolená hodnota v % | ||||
|---|---|---|---|---|---|
| Relativní chyba | Relativní rozlišitelnosti indikačního zařízení a | ||||
| přesnosti q | opakovatelnosti b | zpětného chodu a) v | nuly f0 | ||
| 0,5 | ± 0,5 | 0,5 | ± 0,75 | ± 0,05 | 0,25 |
| 1 | ± 1,0 | 1,0 | ± 1,5 | ± 0,1 | 0,5 |
| 2 | ± 2,0 | 2,0 | ± 3,0 | ± 0,2 | 1,0 |
| 3 | ± 3,0 | 3,0 | ± 4,5 | ± 0,3 | 1,5 |
| a) Podle 5.2.3.8 je relativní chyba zpětného chodu stanovena pouze na požádání. | |||||
2.1.2. Requirements for test machine strength measurement systems
The verification of the test machine strength system for forces above 500 N shall be carried out solely with an etalon load gauge. Verification of the test machine strength system for loads up to 200 N can be performed with an etalon load gauge or an etalon load vessel.
2.1.2.1 Etalon load meters
The etalon load cell class shall be equal to or higher than the class for which the test machine is verified. The accuracy class of the etalon load cell shall be specified in the calibration sheet of the etalon load cell for the load cell. In this calibration sheet the reference value of the output data of the etalon load gauge and the expanded uncertainty of its calibration shall be given below. Table 2 shows the classes of etalon load meters to be used to verify the test machine of the relevant class.
Table 2. Allocation of etalon load meters for test machine class
| Třída zkušebního stroje | Etalonový siloměr použitý při ověřování | |
|---|---|---|
| Třída etalonového siloměru | Největší hodnota rozšířené nejistoty ověřovaného etalonového siloměru % | |
| 0,5 | 0,5 | ± 0,12 |
| 1 | 0,5, 1 | ± 0,24 |
| 2 | 0,5, 1, 2 | ± 0,45 |
| 3 | 0,5, 1, 2 | ± 0,45 |
2.1.2.2 Etalon loading bodies
In the case of verification of the test machine strength system by ethalon load bodies, the relative expanded uncertainty of the acting force shall be less than or equal to ± 0,1%.
The exact equation indicating the load force F (N), caused by an etalon load body or an etalon load system of m (kg), is:
F = m · gn · 1-ρairρm
If the effect of the air lift on the etalon load bodies is neglected, the load force calculated from the following equation will be 0.02% greater than the actual force acting. We can calculate this force using the following equation:
F = m · gn
The relative error of this force shall be calculated using the formula:
IUPAC Name
The standard uncertainty of force realised by an etalon load system shall be determined from the following equation:
uF = m · ugn + g · um,
where uF is the standard uncertainty of the force realised by the ethalon load bodies in N,
m is the mass of all etalon load bodies used for implementing the force in kg,
gn is the local acceleration of gravity at the test machine verification site in m.s-2,
um is the mass uncertainty of the etalon load bodies in kg,
ugn is the standard uncertainty for determining the acceleration of gravity at the verification site in m.s.2
2.2 TECHNICAL REQUIREMENTS
2.2.1. Construction
2.2.1.1. Test machine frame
The frame of the test machine shall be so designed as to ensure unambiguous application of the test force.
2.2.1.2 Fastening systems
The design of clamping systems shall allow the axis force to be applied.
2.2.1.3. Movement mechanism
The movement mechanism of the transverse must allow a constant and continuous change of force. It must also allow any force to be set with sufficient precision. The motion mechanism shall allow the rapid deformation of the test body required to determine the specific mechanical properties of the materials.
2.2.1.4 Test machine load equipment
The loading devices are permanently installed in the test machine or are special components thereof. The plane deviation is 0,01 mm, at a measured distance over 100 mm.
If the test equipment of the test machine is made of steel, its surface hardness shall be greater than or equal to 55 HRC.
If the test machines used for tests of bending-sensitive test samples are applied, the upper plate of the loading device shall be fixed in a ball joint which is practically free of movement in the unladen state and easily adapts the angle to approximately 3 °.
2.2.1.5 Analog scale
The width of the marks on the scale shall be the same and the width of the marker shall be approximately the same as the width of the scale marks.
2.2.1.6 Numerical scale
The numerical scale shall be clearly legible and shall show a stable value. If the test machine is unloaded, the engines and control systems are functional, the indicator should not fluctuate by more than one increment.
2.2.1.7. Position of test machine
The test machine shall be so constructed as not to be adversely affected by ambient interference conditions (vibrations, electrical influences, corrosion effects, excessive local temperature fluctuations, etc.).
2.2.1.8 Exhaust load bodies
Exhaust load bodies shall be clearly identifiable. If separable pendulum devices are used, they shall be properly marked for good identification.
2.2.2. Labels and marks
The manufacturer's well-accessible identification table marked with:
(a) the manufacturer;
(b) a type of test machine,
(c) the year of manufacture;
(d) production numbers;
(e) nominal forces.
If multiple force sensors are used for the test machine, each sensor shall be marked.
3 TYPE APPROVAL
3.1. Type-approval procedure
3.1.1. Requirements for the documentation submitted
The applicant shall provide documentation in accordance with the specific legislation1).
3.1.2. Samples
Since it is a costly device which is supplied in a small number of pieces, it is waived to deliver a special sample. Tests for approval shall be carried out on a supplied test machine or the same type of test machine with the manufacturer.
3.1.3. Requirements for test equipment
The test equipment referred to in paragraph 2.1.2 shall be used to perform the tests.
3.1.4 Environmental conditions
The normal conditions for the position of the test machine shall be ensured during the tests. The test temperature shall be (23 ± 5) ° C.
3.1.5 Allowed errors
The limit values for relative errors of the test machine force measuring device are given in Table 1.
3.1.6. Test procedure
The tests shall be carried out in accordance with paragraph 4.
3.2. Type-approval certificate
The particulars of the type-approval certificate shall be laid down in a separate legislative act (2).
4 VERIFICATION
The procedure for initial and subsequent verification shall be the same.
Verification of the test machine shall consist of:
(a) general assessment of the test machine, including its accessories for force application;
(b) verification of the force measuring system.
4.1 General assessment of the test machine
Verification of the test machine may be carried out if the test machine is in the required technical condition. For this purpose tests shall be carried out according to paragraphs 4.1.1 to 4.1.4.
4.1.1. Visual examination
The visual examination shall examine:
(a) that it is not significantly worn, that there is no failure of the components of the chassis or clamps and that the installed columns and the fixed beam have not been released;
(b) whether the ambient conditions (vibrations, electrical influences, corrosion effects, local temperature fluctuations, etc.) have an adverse effect on the test machine; and
(c) whether the range bodies of the test machine, range springs or tensimetric sensors (if separable) are clearly identifiable and do not allow substitution.
4.1.2 Inspection of test machine design
It shall be checked and ensured that the structures and clamping systems allow the axis force to be applied.
4.1.3 Inspection of the transverse motion mechanism
A check shall be made to ensure that the movement mechanism of the cross-section enables a constant and continuous change of force and allows the individual forces to be adjusted with sufficient precision.
The motion mechanism should allow for a sufficiently rapid deformation of the test body required to determine specific mechanical properties.
4.1.4 Check of test machine loading equipment
The loading devices are permanently installed in the test machine or are separate parts of the test machine.
Before checking the force measuring system, it is necessary to determine whether the load device performs its function in accordance with the test machine requirements.
Deviation of planes is 0,01 mm, at measured distance over 100 mm.
If loading devices are made of steel, it shall be determined whether their hardness is greater than or equal to 55 HRC.
If the test machines used for testing bending-sensitive test samples are test machines, it shall be checked that the top plate of the loading device is fixed in a ball joint which is practically free of movement in an unladen state and is easily adjusted to an angle of approximately 3 °.
4.2 Verification of test machine strength measurement system
4.2.1 General
The verification shall be carried out for each force range used and with all force indicators used. Each accessory (e.g. indicator, recorder, if applicable) which may influence the force measurement system shall be tested in accordance with clause 4.2.3.6.
If the test machine has several force measurement systems, each system shall be considered a separate test machine. The same procedure shall be used for two-piston hydraulic machines.
Verification shall be carried out with the following exceptions: If the tensile force of the shredding machines to be verified is less than 200 N, an etalon load vessel may be used.
If more than one force cell is to be used to verify the force line, then the maximum force used for the lower force cell shall be the same as the minimum force used for the higher force cell. When an etalon load cell set is used to verify forces, this set shall be considered as one etalon gauge.
The verification shall preferably be performed for constant values of indicated forces, Fi. If this method is impracticable, the verification shall be performed for constant values of actual forces. The verification is carried out at a slowly increasing force.
The statistics used for the verification shall have a valid calibration sheet. The requirements for etalones are set out in Section 2.1.2.
4.2.2 Determination of differentiability
4.2.2.1 Analog scale
The differentiability of r of the indicator is determined from the ratio between the width of the indicator and the distance between the midpoints of the two adjacent marks of the analogue scale (value of the piece). The recommended ratios are 1: 2, 1: 5 or 1: 10, for the estimation of one tenth of the part of the analog scale, a length of 2,5 mm or more is required.
4.2.2.2 Numerical scale
The smallest change in the data shown by the digital indicator is considered to be distinguishable, provided that the test machine is unloaded, the engines and the control system are functional and the indicator does not fluctuate by more than one increment.
4.2.2.3. Intermediate reading
If the reading data changes by more than the previously calculated value of differentiability, the differentiability r shall be considered equal to one half of the range of variations plus one increment.
This only defines the differentiability caused by the failure of the measurement system and does not take into account the errors of the control system, i.e. the hydraulic machine.
For the automatic ranges of test machines, changes in indicators shall be decided by differentiability or by achieving a change in the measurement system.
4.2.2.4. Unit of differentiability
Differentiability r, must be expressed in units of force.
4.2.2.5 Determination of the relative resolution of the indicator device
Relative differentiability a, indicator device is defined by:
a = rF · 100,
where r is the differentiability in units of force
F is the force at the measured point.
This relative differentiability shall be determined at each verification point and shall not exceed the values given in Table 1 for the class of test machine tested.
4.2.3. Test procedure
4.2.3.1. Etalon load gauge compatibility
Balancing minimises any bending effects when loading on an etalon load meter in the test machine. If the test machine does not have an integral ball area, attach the top plate with the ball joint to the etalon load-meter to compensate for the etalon load-meter.
4.2.3.2 Temperature compensation
The verification shall be carried out at an ambient temperature between 10 ° C and 35 ° C. This temperature shall be recorded in the certificate.
An etalon load gauge shall be provided for a sufficient period of time to balance the temperature. The temperature of the etalon load cell shall remain stable within ± 2 ° C during each verification cycle. If necessary, the data shall be heat corrected.
4.2.3.3. Pre-loading in the test machine
The test machine, with an etalon load gauge in the test position, shall be at least three times loaded from zero to the maximum measured force.
4.2.3.4. Verification procedure
The following method is usually used: the force of Fi, given by the indicator device, is set on the test machine and the actual force F given by the etalon force gauge shall be recorded.
If this method cannot be used, the actual force The F-meter shall be set on the test machine and the Fi force indicated by the indicator device of the verified machine shall be recorded.
4.2.3.5 Application of individual forces
Three series of loading measurements shall be carried out. For test machines tested at no more than five points of the force scale, no relative error value shall exceed the values given in Table 1 for certain classes. For test machines verified at more than five points of the force scale, each series of measurements shall contain at least five individual forces evenly distributed between 20% and 100% of the maximum scale force.
If the verification is carried out for forces below 20% of the maximum force of the range, a measurement of the force shall be made at approximately 10%, 5%, 2%, 1%, 0,5%, 0,2% and 0,1% from the lower range of force, including the lower limit of the verified range.
The lower limit of the measuring range is defined by the multiple differentiability r:
(a) 400 for class 0,5;
(b) 200 for Class 1;
(c) 100 for Class 2; and
(d) 67 for Class 3.
Before each series of measurements, the etalon load gauge may be rotated by an angle of 120 ° and measured at the preliminary load.
The arithmetic mean of the values obtained for each series of measurements shall be calculated for each individual force. The relative accuracy error and the relative repeatability error of the test machine measuring system shall be calculated from these mean values.
The reading indicator shall be adjusted to zero before each series of measurements. Zero must be deducted approximately 30 seconds after complete relief. In the case of an analogue indicator device, it shall also be checked whether the indicator is freely rocking around zero and, if a digital indicator device is used, that every drop below zero, such as the indicator sign (+ or -), is immediately reported.
The relative zero error shall be calculated for each series of measurements according to the following equation:
f0 = Fi0FN · 100.
4.2.3.6 Verification of accessories
The good operating condition and friction resistance of mechanical accessories (indicator, recorder) shall be checked by one of the following methods depending on whether the machine is commonly used with or without accessories:
(a) Test machine normally used with accessories: three series of measurements shall be made with increasing force (see clause 4.2.3.5) with attached accessories for each force range used and one additional series of measurements without accessories for the smallest range used.
(b) Test machine normally used without accessories: three series of measurements shall be made with increasing force (see clause 4.2.3.5) with disconnected accessories for each measuring range used and one additional series of measurements with attached accessories for the smallest range used.
In both cases, a relative error of accuracy q, for three series of measurements, and a relative error of repeatability b, shall be calculated from four series. The values obtained shall correspond to the values in Table 1 for the class under consideration and the following additional conditions shall be met:
for verification with - constant declared force:
100 · Fi-FcFc ≤ 1,5 · q
for a constant actual force verification:
100 · Fic-FF ≤ 1,5 · q
The value q in the equation is the maximum permissible value given in Table 1 for the class considered.
4.2.3.7 Verification of the influence of different position of the plunger
For hydraulic test machines where the hydraulic drive pressure is used to measure the test force, the influence of different piston positions for the smallest measuring range of the machine used during three series of measurements shall be checked. The position of the plunger shall be different for each series of measurements.
In the case of a two-piston hydraulic test machine, it is necessary to take into account both pistons.
4.2.3.8 Determination of the relative reverse error
If a relative error of reversing is required in, it shall be determined by checking the same individual forces, first when loaded and then when relieved. In this case, the test machine shall also be verified for relief.
The difference between the values obtained during loading and the relief allows to calculate the relative error of the reverse operation using the following equation:
v = F '-FF ^ · 100
or, in the case of a specific verification carried out by constant actual force:
v = F'i-FIF · 100.
The test shall be carried out for the smallest and greatest range of test machine strength.
4.2.4 Evaluation of the strength indicator device
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Regulation Information
| Citation | Decree No. 70 / 2004 Coll., laying down requirements for shredding machines and presses |
|---|---|
| Regulation Type | - |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 24.02.2004 |
|---|---|
| Effective from | 01.03.2004 |
| Effective until | - |
| Status | Valid |
The regulation text is for informational purposes only.
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