BS EN 60613:2010 pdf free download Electrical and loading characteristics of X-ray tube assemblies for medical diagnosis
3.21
NOMINAL CT SCAN POWER INDEXNOMINAL CTSPI
CTSPI,calculated for a lower limit of the LOADING TIME of 1 s, an upper of the LOADING TIME of25 s and a cYCLE TIME of 10 min
3.22
RADIOGRAPHIC RATINGs
for the operation of an X-RAY TUBE,SPECIFIED combinations of conditions and LOADINGFACTORs,under which the sPECIFIED limits of loadability of the X-RAY TUBE are attained
3.23
SINGLE LOAD RATING
highest permitted X-RAY TUBE LOAD given by a relationship between constant ANODE INPUTPOwER and LOADING TIME for one LOADING under sPECIFIED conditions
3.24
SERIAL LOAD RATING
highest permitted X-RAY TUBE LOAD given by the relationship between ANODE INPUT POWER andLOADING TIME for the total of a sPECIFIED series of individual X-RAY TUBE LOADS with sPECIFIEDLOADING FACTORs under sPECIFIED conditions
4Presentation of the electrical characteristic
4.1X-RAY TUBE VOLTAGE
The X-RAY TUBE VOLTAGE shall be given as the peak value, in kilovolts.
4.2 NOMINAL X-RAY TUBE VOLTAGE
The NOMINAL X-RAY TUBE VOLTAGE shall be given as the peak value,in kilovolts.
4.3X-RAY TUBE CURRENT
The X-RAY TUBE CURRENT shall be given as the average value in milliamperes.
4.4CATHODE EMISSION CHARACTERISTIC
CATHODE EMISSION CHARACTERISTIcs are given as a family of curves in which the X-RAY TUBECURRENT is shown as a function of the FILAMENT CURRENT and,if appropriate,of furthercharacteristics of the cATHODE,each curve corresponding to an X-RAY TUBE vOLTAGE whilespecifying its waveform,and other factors as appropriate. lf appropriate,the relationshipbetween FILAMENT CURRENT and filament voltage shall be indicated and also its dependenceon other characteristics of the cATHODE.
4.5ENVELOPE characteristics4.5.1 ENVELOPE CURRENT
lf the ENVELOPE CURRENT is to be stated, it shall be given as the percentage value of X-RAYTUBE CURRENT under sPECIFIED conditions.
4.5.2ENVELOPE VOLTAGE
lf the ENVELOPE VOLTAGE is to be stated, it shall be given in kilovolts with respect to earth.
5 LOADING of an X-RAY TUBE
5.1 LOADING TIME
5.1.1 Units
The LOADING TIME shall be given in seconds.
5.1.2 Measurement
LOADING TIME is measured as the time interval between:
– the instant that the X-RAY TUBE VOLTAGE has risen for the first time to a value of 75 % ofthe peak value; and
– the instant at which it finally drops below the same value.
lf LOADING is controlled by electronic switching of the HIGH VOLTAGE,using a grid in anelectronic tube or in the X-RAY TUBE, the LOADING TIME may be determined as the time intervalbetween the instant when the TIMING DEVICE generates the signal to start the IRRADIATION andthe instant when it generates the signal to terminate the lRRADIATION.
lf LOADING is controlled by simultaneous switching in the primaries of both the high-voltagecircuit and the heating supply for the filament of the X-RAY TUBE, the LOADING TIME shall bedetermined as the time interval between the instant when the X-RAY TUBE CURRENT first risesabove 25 % of its maximum value and the instant when it finally falls below the same value.
NOTE1 See also definition 3.11.
NOTE 2 The LOADING TIME is preferably measured at the tube input to minimise the influence of Hv-cable-capacitance.
NOTE 3 For field-testing,a reasonable approximation of the LOADING TIME can be obtained by measuring theIRRADIATION TIME, for which the sPECIFIc method according to the definition in lEC 60601-1-3:2008 is chosen in thisInternational Standard as the time period during which the AlR KERMA RATE exceeds 50 % of its peak value.
5.2cYcLE TIME
The cYcLE TIME shall be given in minutes or seconds,as appropriate.
6 Input power
6.1 A NODE INPUT POWER
The ANODE INPUT POWER shall be given in kilowatts for SPECIFIED conditions of LOADING .
6.2 N OMINAL ANODE INPUT POWER
The NOMINAL ANODE INPUT POWER shall be given in kilowatts.
6.3 N OMINAL RADIOGRAPHIC ANODE INPUT POWER
The NOMINAL RADIOGRAPHIC ANODE INPUT POWER shall be given in kilowatts.
6.4 N OMINAL CT ANODE INPUT POWER
The NOMINAL CT ANODE INPUT POWER shall be given in kilowatts.
6.5 X- RAY TUBE ASSEMBLY INPUT POWER
The X- RAY TUBE ASSEMBLY INPUT POWER shall be given in watts.
6.6 N OMINAL CONTINUOUS INPUT POWER
The NOMINAL CONTINUOUS INPUT POWER shall be given in watts.
Unless otherwise SPECIFIED , the ambient temperature shall be between 20 °C and 25 °C.
6.7 C ONTINUOUS ANODE INPUT POWER
The CONTINUOUS ANODE INPUT POWER shall be given in watts.
6.8 CT SCAN POWER INDEX (CTSPI)
The CT SCAN POWER INDEX shall be given in kilowatts.
6.9 N OMINAL CT SCAN POWER INDEX ( NOMINAL CTSPI)
The NOMINAL CT SCAN POWER INDEX shall be given in kilowatts.