Fluke Biomedical Victoreen 07-494, Руководство оператора

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Victoreen 07-494
Operators Manual
4-2
NOTE
If a kVp value is not displayed, try doubling the
exposure time or decreasing the FDD by 30%.
9. Observe any displayed warnings, including flashing decimals or a low battery indication.
NOTE
Warning indications are interpreted on the top
panel and in the following paragraphs.
The Digital kVp Meter has an auto reset feature. It senses when a new exposure takes place, resets the
display for a new reading and turns on the Auto Reset LED for 0.5 seconds or the duration of the
exposure, whichever is greater.
4.2 Interpreting Front Panel Warning Indications
Front panel warning indications are listed in Table 4-2.
A flashing decimal point above the A on the front panel indicates that the measured kVp is above the
calibrated range; that is, the kVp is above 150 kVp with the range selector in the 80 to 150 kVp setting or
above 90 kVp with the range selector in the 50 to 90 kVp setting.
A flashing decimal point above the B on the front panel indicates that the measured kVp is below the
calibrated range; that is, that the kVp is below 80 kVp with the range selector in the 80 to 150 kVp setting
or below 50 kVp with the range selector in the 50 to 90 kVp setting.
Indication
A
Explanation
Measured kVp > calibrated range.
B
C/D
(Display
≠
00.00)
Measured kVp < calibrated range.
Beam intensity too high; measurement time too
short.
C/D
Display = 00.0
Beam intensity too low; measurement time too long.
A flashing decimal point above the C/D on the front panel with a displayed value other than 00.0 indicates
that beam intensity is too high and the measurement is completed with less than 50 ms of radiation
waveform. Increase the FDD or decrease the mA to produce more accurate results. This is particularly
important for single-phase x-ray machines because the radiation spectrum changes dramatically
throughout e duration of 4 pulses. If the measured waveform contains less than 6 pulses of single-phase
rectification, a partial pulse has a significant contribution to the value of the average of the pulses. It is
less important for 3 phase machines because the radiation spectrum remains relatively constant
throughout the exposure.