IEC 62976-2021 Industrial non-destructive testing equipment – Electron linear accelerator.
4.3 Operating conditions
4.3.1 Environmental requirement
• environment temperature: (5 to 40) °C;
• relative humidity: ≤90 %.
4.3.2 Power supply
• voltage: 380 V ±1 0 % three-phase four-wire AC system;
• frequency: 50 Hz ±2 % / 60 Hz ±2 %;
• power supply: it is put forward in the product manual according to the accelerator model;
• grounding resistance: special grounding resistance of modulator is less than 4 Ω.
5 Technical requirements
5.1 Appearance
The surface shall be smooth, uniform color, no obvious scratches, bumps or holes.
5.2 Control system
5.2.1 Design principle
The design of the control system shall ensure the safety of the operator, the device and the
delivered dose.
5.2.2 Operation of start and stop
Operation of X-ray source start and stop shall be executed in the control console.
5.2.3 Functions of control system
The basic functions of the control system shall include:
• normal start-up and shut-down,
• display of the status of normal, fault, alarm and auto-stop,
• display of the main operational parameters,
• safety interlock,
• emergency stop.
5.3.4 X-ray beam focal spot
The diameter of the X-ray spot shall be less than or equal to 2,0 mm when the X-ray beam energy is less than 9 MeV; the diameter of X-ray spot shall be less than or equal to 3,5 mm when X-ray beam energy is equal to or higher than 9 MeV.
5.3.5 X-ray beam asymmetry
X-ray beam asymmetry shall be less than 3 % at 7,5° away from X-ray beam center axis when the X-ray beam energy is less than or equal to 9 MeV; X-ray beam asymmetry shall be less than 5 % at 6° away from X-ray beam center axis when X-ray beam energy is higher than
9 MeV.
5.3.6 X-ray sensitivity
In the range of the X-ray beam energy and the corresponding equivalent steel thickness stated in Table 5, X-ray sensitivity shall be less than 1 % as determined by linear densitometry for imaging detection.
5.3.7 Dose leakage
a) X-ray dose leakage
A measure of leakage is given by the ratio of X-ray dose rate 1 m away from the target in a variety of directions to the X-ray dose rate on the central beam axis. This shall be expressed as a percentage and shall be less than 0,1 %.
b) Neutron dose leakage (if the accelerator energy is higher than or equal to 1 0 MeV) Neutron dose rate shall be no more than 0,01 mSv/h 1 m away from the target beyond the X-ray field formed by the forward collimator and no more than 0,001 mSv/h in other places.
5.4 Electrical safety
5.4.1 Protective grounding
Separated electric shock protection is essential. The resistance between metal surface and grounding terminal shall not be more than 0,1 Ω.IEC 62976  pdf download.