application guidelines
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Usage instructions
grid control of technical X-ray tubes
Focal spots of technical X-ray tubes of Petrick GmbH mentioned in the provided data sheets are made principally without grid control. The stated focal spot size in standard operation correspond with the technical specification. Grid control is still possible.
operation with grid control
The X-ray tube can be set into standby through use of the grid control (I tube = 0 mA).
This can be realized by feeding a negative voltage between modular electrode and filament (the respective voltage depends on the X-ray tube type).
operation without grid control
Operation without grid control is possible when the modular electrode is applied to the filament ground.
lifetime
lifetime of our X-ray tubes
The lifetime of an X-ray tube is limited by several possible causes of failure.
overheating beyond normal operating temperature
This causes a minimization of the high vacuum by sublimation of target material.
vaporization of the filament
The most important limitation of the lifetime is the vaporization of the filament.
To reach the filament temperature necessary for an electron emission, it is heated electrically. Because of the temperature dependent natural vaporization rate of the filament material, the cross section of the filament wire becomes smaller over time, which eventually leads to filament break.
The speed of the vaporization process and the thusly to be expected service life depends directly on the filament current. The high voltage power supply connected to the X-ray source must have control circuit which secures a constant tube current. It is also important that the filament current is limitable upwards, so that overheating of the filament is precluded when turned on.
The filament current recommended for Petrick X-ray tubes are stated in the respective data sheets.
Durability
warm up process for X-ray sources
Warm-up processes for X-ray sources are crucial not only to ensure optimal performance but also to maximize the lifetime of the devices.
50 kV X-ray sources out of operation for < 1 month
50 kV X-ray sources out of operation for > 1 month
60 kV X-ray sources out of operation for < 1 month
60 kV X-ray sources out of operation for > 1 month
80 kV X-ray sources out of operation for < 1 month
80 kV X-ray sources out of operation for > 1 month
Protection
protection against overheating of the X-ray source
A temperature switch integrated into the Petrick X-ray tube assembly protects the built-in X-ray tube from overheating. Our X-ray tube systems offer various cooling options for a wide range of applications.
When using Petrick X-ray tubes without protection housing the user is responsible for a sufficient cooling.
test
X-ray tube assembly rapid test
For goods receipt inspection, in the case of errors or failures of the X-ray tube assembly please conduct the following test. Please contact our quality management for further failure analysis.
test
Connect a laboratory power supply with a preset current of 1.3 A to the X-ray tube using the provided heating cable, according to the above circuit.
result
X-ray tube okay
I = 1.3 A
U > 1.0 V
X-ray tube fault (vacuum loss)
I = 1.3 A
U < 1,0 V
X-ray tube fault (filament defect)
I = 0.0 A
Do you have questions about our products?
Get in touch with us. Our contact persons will make an effort to provide feedback as soon as possible
+49 (0) 367 41 5868 0
info@petrickgmbh.de
