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Fluke Biomedical Victoreen 07-494 Operator's Manual

Wide-range digital kvp meter
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Victoreen 07-494
Wide-Range Digital kVp Meter
Operators Manual
December 2006
Manual No. 168001 Rev. 4
©2006 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

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Summary of Contents for Fluke Biomedical Victoreen 07-494

  • Page 1 Victoreen 07-494 Wide-Range Digital kVp Meter Operators Manual December 2006 Manual No. 168001 Rev. 4 ©2006 Fluke Corporation, All rights reserved. Printed in U.S.A. All product names are trademarks of their respective companies...
  • Page 2 Fluke Biomedical Radiation Management Services 6045 Cochran Road Cleveland, Ohio 44139 440.498.2564 www.flukebiomedical.com/rms...

  • Page 3: Table Of Contents

    Table of Contents Section 1: General Information................... 1-1 Product Description ..................1-1 Specifications....................1-2 Section 2: Getting Started................... 2-1 Receiving Inspection..................2-1 Storage ......................2-1 Routine Cleaning ..................2-1 Indicators and Controls ................2-2 Section 3: Theory and Applications ................3-1 General ......................
  • Page 4 (Blank page)

  • Page 5: General Information

    General Information Product Description Section 1 General Information 1.1 Product Description The Model 07-494 Wide-Range Digital kVp Meter (Figure 1-1) is a portable, battery operated unit which non-invasively measures the effective peak potential applied to a tungsten target diagnostic x-ray tube. It uses two differentially filtered x-ray detectors whose ratio of integrated outputs is calibrated over the ranges of 50 to 90 kVp and 80 to 150 kVp.

  • Page 6: Specifications

    Victoreen 07-494 Operators Manual 1.2 Specifications Range Low: 50 kVp to 90 kVp High: 80 kVp to 150 kVp Resolution 0.1 kVp ± 3% or 3 kV, whichever is greater (tungsten target x-ray tube Accuracy with 4.5 mm Al total filtration)
  • Page 7 Victoreen 07-494 Operators Manual Figure 1-2. mAs vs. kVp, Minimum Requirements (Typical Single Phase X-ray Unit)
  • Page 8 Victoreen 07-494 Operators Manual (Blank page)

  • Page 9: Getting Started

    Upon receipt of the instrument: 1. Inspect the carton(s) and contents for damage. If damage is evident, file a claim with the carrier and contact Fluke Biomedical, Radiation Management Services at 440.248.9300. 2. Remove the contents from the packing material.

  • Page 10: Indicators And Controls

    Victoreen 07-494 Operators Manual 2.4 Indicators and Controls Top Panel The top panel (Figure 2-1) includes brief operating instructions, beam center indication, display guide for warning indicators A through D, and the range selector switch. The range selector switch allows the operator to select the appropriate kVp range for the measurement.
  • Page 11 Getting Started Indicators and Controls Figure 2-2. Front Panel Rear Panel Refer to Figure 2-3 for rear panel layout. Battery Access Cover: The battery access cover is located on the rear panel. Refer to Section 5, Maintenance for battery replacement procedures. NOTE Be sure the unit is turned OFF before removing the batteries.
  • Page 12 Victoreen 07-494 Operators Manual (Blank page)

  • Page 13: Theory And Applications

    Theory and Applications General Section 3 Theory and Applications 3.1 General The kVp measurement is computed from a measurement of the linear absorption coefficient (µ) of the hardened x-ray beam. As the kV increases, µ increases, as discussed in the following paragraphs. An x-ray beam is composed primarily of two parts - the bremsstrahlung radiation and the characteristic radiation.

  • Page 14: Waveform Effects

    Victoreen 07-494 Operators Manual 3.3 Waveform Effects Beam spectrum changes also occur with different waveforms. Single-phase waveforms display different readings than three phase waveforms, depending on the position of the range selector switch. Correction for waveform effect is made by selecting the appropriate position (i.e., single phase or three phase) using the front panel phase selection switch.

  • Page 15: Detector Positioning

    Theory and Applications Detector Positioning 3.6 Detector Positioning The kVp Meter should be positioned in the center of the beam. The measurement area of the meter is 2 square inches, and is located on the top panel of the unit. Measurements made on other parts of the beam will result in inaccurate readings due to the fact that the beam spectrum is different for different parts of the beam.
  • Page 16 Theory and Applications Applications To eliminate time as a variable, decrease the FDD and mA while holding time constant. Utilizing the inverse square law: = FDD X SQRT (mA where: = FDD to be used with new mA, = FDD used with the maximum mA, and SQRT = Square root.
  • Page 17 Theory and Applications Applications Table 3-4. kVp vs. Time Study at 300 mA T (sec) ISF X FDD FDD (Inches) Measured kVp 0.500 1.000 36.0 0.250 0.707 25.5 0.125 0.500 18.0 0.067 0.365 13.1 mAs Reciprocity Corrections A mAs reciprocity examination of an x-ray system involves variation of the mA or time or both simultaneously.
  • Page 18 Theory and Applications Applications Problem Symptom Preheat problems Waveform intensity continues to increase over the first few cycles. Arcing Waveform exhibits sharp rises and spikes with a duration of 10 to 1000 microseconds. Overshoot Problems Waveform exhibits overshoot on the first 2 or 3 pulses (3 phase machine).

  • Page 19: Operation

    Operation Making a Measurement Section 4 Operation 4.1 Making a Measurement Use the following procedure to make a kVp measurement: 1. Turn the power switch to the ON position. The following should appear on the display: 00.0 NOTE If the low battery indication is displayed, or if the display fails to respond, replace the battery.

  • Page 20: Interpreting Front Panel Warning Indications

    Victoreen 07-494 Operators Manual 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.

  • Page 21: Viewing The Waveform Output

    Operation Interpreting Front Panel Warning Indications NOTE For displayed values greater than 95 kVp a flashing decimal point above the C/D on the front panel may be impossible to avoid for any combination of mA or distances. The sensitivity of the kVp Meter above 95 kVp increases such that the mAs requirements become very low at short distances.
  • Page 22 Victoreen 07-494 Operators Manual (Blank page)

  • Page 23: Calibration And Adjustments

    Calibration and Adjustment Low Battery Threshold Adjustment Section 5 Calibration and Adjustment This instrument has been factory calibrated. Recalibration should be performed by the factory or a qualified calibration facility every 12 months. Other than calibration, there are six potentiometers which may require adjustment.
  • Page 24 Victoreen 07-494 Operators Manual 50 – 90 kVp 80 - 150 kVp Calibration Calibration Adj ustments Adjustments d R3) Three Phase Adjustments (R19 and R60) Low Battery Threshold Adjustment (R25) Below Batter Figure 5-1. Adjustment and Test Point Locations...

  • Page 25: End Of Shot Adjustment

    Calibration and Adjustment End of Shot Adjustment 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.
  • Page 26 Victoreen 07-494 Operators Manual 7. Adjust R6 until the display reads 85 kVp. 8. Set the x-ray machine to 140 kVp, 50 mA, and 0.3 seconds. 9. Make an exposure. NOTE If the C/D decimal point is flashing, indicating that...

  • Page 27: Maintenance And Troubleshooting

    Maintenance and Troubleshooting Battery Replacement Section 6 Maintenance and Troubleshooting 6.1 Battery Replacement When the internal battery no longer provides sufficient voltage for proper operation, a LOW BAT indicator will appear in the upper left corner of the display. When this indication appears replace the battery as follows: 1.

  • Page 28: Performance Verification (Calibration Constancy)

    Victoreen 07-494 Operators Manual 6.3 Performance Verification (Calibration Constancy) In this section, two methods are described for verifying the accuracy of the kVp meter. Both methods require a careful collection of installation data and periodic re-measurement of that data. The voltage divider method is more direct than the multiple x-ray machine method.

  • Page 29: Verifying Supply Voltages

    Maintenance and Troubleshooting Performance Verification (Calibration Constancy) 4. Periodically (every 6 months) or when a serious discrepancy occurs, repeat Steps I through 3 to determine which piece of equipment is in error. NOTE If the kVp meter suddenly produces different results from previous tests on only one machine, then there is a strong probability that the kVp Meter is operating correctly.
  • Page 30 Victoreen 07-494 Operators Manual CH1 = TP1 CH2 = TP8 Setup: Single phase x-ray machine 74.5 kVp @ 300 mA 28 “ SDD 20ms -328mV CH1 CH1gnd CH2gnd Figure 6-2. Oscilloscope Waveform A...
  • Page 31 Maintenance and Troubleshooting Verifying Supply Voltages CH1 = TP1 CH2 = TP9 Setup: Single phase x-ray machine 74.2 kVp @ 300 mA 28 “ SDD 20ms 563mV CH1gnd CH2gnd Figure 6-3. Oscilloscope Waveform B...
  • Page 32 Victoreen 07-494 Operators Manual CH1 = TP1 CH2 = TP2 Setup: Single phase x-ray machine 75.5 kVp @ 300 mA 28 “ SDD 20ms 563mV CH2 CH1gnd CH2gnd Figure 6-4. Oscilloscope Waveform C...
  • Page 33 (Blank Page)
  • Page 34 Fluke Biomedical Radiation Management Services 6045 Cochran Road Cleveland, Ohio 44139 440.498.2564 www.flukebiomedical.com/rms...

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