Fluke Biomedical Victoreen 07-494, Руководство оператора

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5
Calibration and Adjustment
End of Shot Adjustment
5-3
5.2 End of Shot Adjustment
R33 provides adjustment of the radiation detection diode sensitivity. Use the following procedure:
1. Connect the positive lead of a DVM to TP3.
2. Connect the negative lead of the DVM to TP4.
3. Record the DVM reading.
4. Connect the positive lead of the DVM to TP8.
5. Adjust R33 to obtain a reading on the DVM equal to 50% of the reading recorded in Step 3 (at
TP3).
NOTE
The reading obtained in Step 5, after adjustment of
R33 should be between 1.2 and 1.5 V.
5.3 50 - 90 kVp Calibration
The adjustments for the 50 - 90 kVp range are R4 and R5. An independent accurate means of
measuring the kVp of the x-ray machine is necessary for proper calibration. The kVp meter must be
calibrated at 50 kVp and 85 kVp (+1%) to be within specification. Use the following procedure:
1. Set the front panel phase switch for single-phase or three-phase depending on the type of x-ray
machine used for calibration.
2. Set the range selector switch to the 50 - 90 kVp range.
3. Remove the cover from the meter.
4. Locate the meter at an FDD of 24 inches.
5. Set the x-ray machine to 50 kVp, 300 mA, and 1.5 seconds.
6. Make an exposure.
7. Adjust R5 until the display reads 50 kVp.
8. Set the x-ray machine to 85 kVp, 300 mA, and 0.3 seconds.
9. Make an exposure.
10. Adjust R4 until the display reads 85 kVp.
11. Repeat Steps 5 through 10 until the readings are accurate.
5.4 80 - 150 kVp Calibration
The two adjustments for the 80 kVp to 150 kVp range are R3 and R6. In this range the kVp meter must
be calibrated at 85 kVp and 140 kVp (±1%) to be within specification. Use the following procedure:
1. Set the front panel phase switch for single-phase or three-phase depending on the type of x-ray
machine used for calibration.
2. Set the range selector switch to the 80 - 150 kVp range.
3. Remove the cover from the meter.
4. Locate the meter at an FDD of 24 inches.
5. Set the x-ray machine to 85 kVp, 50 - 100 mA, and 0.3 seconds.
6. Make an exposure.