Fluke Biomedical Victoreen 07-494 Operator'S Manual Download Page 24 | Manualshive

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Fluke Biomedical Victoreen 07-494 Operator'S Manual Download Page 24

Victoreen 07-494
Operators Manual

50 – 90 kVp

Calibration

5-2

Adj

ustments

80 - 150 kVp

Calibration

Adjustments
(R6

d R3)

Low Battery
Threshold
Adjustment
(R25)

Three Phase

Adjustments

(R19 and R60)

R

TP1

R60

TP1

R

R

TP3

TP2

Below

Batter

TP8

R33 TP7

TP4

TP1

TP9

TP5

R19

R

Figure 5-1.

Adjustment and Test Point Locations

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Summary of Contents for Victoreen 07-494

Page 1: ...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: ...ents 3 2 3 6 Detector Positioning 3 3 3 7 Low Battery 3 3 3 8 Applications 3 3 Section 4 Operation 4 1 4 1 Making a Measurement 4 1 4 2 Interpreting Front Panel Warning Indications 4 2 4 3 Viewing the Waveform Output 4 3 Section 5 Calibration and Adjustments 5 1 5 1 Low Battery Threshold Adjustment 5 1 5 2 End of Shot Adjustment 5 3 5 3 50 90 kVp Calibration 5 3 5 4 80 150 kVp Calibration 5 3 Sect...

Page 4: ... Blank page ...

Page 5: ...t 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 The desired range is selected using the range selector on the top of the unit Figure 1 1 Model 07 494 Wide Range Digital kVp Meter ...

Page 6: ... BAT indicator Below Range kVp Flashing middle decimal point Above Range kVp Flashing left decimal point Above Range mAs Flashing right decimal point Below Range mAs Flashing right decimal point and 00 0 display LED Indicators Auto Reset New exposure detected last kVp reading cleared Range Fault Range select sliding filter not properly engaged Controls Power Switch ON OFF Phase Selection Switch Si...

Page 7: ...Victoreen 07 494 Operators Manual 1 2 mA kVp 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: ...nstruction Manual d Part No 010023 Registration Card NOTE If any of the listed items are missing or damaged notify Fluke Biomedical at 440 248 9300 2 2 Storage If necessary to store the kVp meter prior to use pack it in the original container if possible Be sure the storage area is free of corrosive materials vibrations and fluctuations in temperature and humidity Also be sure the environmental sp...

Page 10: ...4 Operation Auto Reset LED The auto reset LED is lit whenever the kVp Meter detects an x radiation The LED will be on for 0 5 seconds or for the duration of the exposure whichever is greater The previous reading is cleared when the LED turns on Range Fault LED The range fault LED is lit whenever the range selector is between ranges or not properly engaged Power Switch ON OFF The power switch is an...

Page 11: ...ned OFF before removing the batteries BNC Connector A BNC connector located on the rear panel provides a signal from the radiation detection diodes The signal can be observed on an oscilloscope during an exposure However the signal lasts only as long as the exposure Therefore a storage scope or camera is required to view the signal for extended periods of time CAUTION Turn off power switch before ...

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Page 13: ...differences with respect to the calibration beam With lower filtration the x ray beam is as hard as the calibration beam and the results are lower With more filtration the beam is harder than the calibration beam and the results are higher Refer to Table 3 1 Table 3 1 Filtration Effects Selected Range kVp Display Increase mm AI 50 90 kVp 65 80 0 34 0 40 80 150 kVp 100 120 0 40 0 45 The results in ...

Page 14: ... 90 18 in 45 cm 36 in 30 cm 80 150 kVp 80 to 100 100 to 150 18 in 45 cm 36 in 30 cm 3 5 mAs Requirements The curves in Figure 1 2 see Section 1 2 Specifications are provided as guidelines for selecting the mAs required for a particular kVp measurement Any mAs beyond the required amount is not used in the measurement To determine the mAs required 1 Locate the kVp to be measured on the horizontal ax...

Page 15: ...acy Determinations With the Digital kVp Meter it is possible to enter a diagnostic x ray room and within one minute determine kVp accuracy for several stations of the x ray machine As a result a significant cause of poor image quality can be immediately diagnosed without affecting patient throughput Calculating Generator Loading Effects In an x ray generator when the load mA changes the kV may als...

Page 16: ...at occurs during the tail end of the exposure A greater portion of the total exposure can be included by increasing the mAs requirement by increasing FDD There is no limit on maximum exposure time To implement this application 1 Select the kV the mA and the longest exposure time to be studied The product of the mA and time should correspond to the minimum mAs requirements determined from Figure 1 ...

Page 17: ...le 3 5 there is a 9 4 increase in mR mAs values There is a 2 5 increase in kVp value which would contribute to an approximate 5 increase in mR output The 94 non linearity in mAs reduces to 9 4 5 4 4 which is acceptable From this analysis it is evident that the mA kV compensation needs correction whereas without this analysis the mA or time looks suspect If the changes in kV and mAs are in the oppo...

Page 18: ...microseconds Overshoot Problems Waveform exhibits overshoot on the first 2 or 3 pulses 3 phase machine Contactor Bounce Waveform peaks contain noise or smaller peaks riding on major peaks Rectifier Imbalance Relative peak heights are different and repeatable i e one high and one low or in a three phase machine high medium low high medium low high medium low Load Effects Waveform exhibits drooping ...

Page 19: ...the fluoroscopic mode the loading on the generator is much lighter than normal and the radiation spectrum more closely resembles that produced by a three phase rather than single phase generator 3 Set the range selector switch located on the top panel to the appropriate range for the kV to be measured 4 Set the desired Focus to Detector Distance FDD using the guidelines listed in Table 4 1 Table 4...

Page 20: ...l 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 ...

Page 21: ...detail in Section 3 Theory and Applications A flashing decimal point the C D on the front panel with a displayed value equal to 00 0 indicates that the minimum mAs requirements have not been met Increase either the time or the mA setting or decrease distance to obtain the required results 4 3 Viewing the Waveform Output The BNC connector on the rear panel provides a signal from the unfiltered radi...

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Page 23: ...lus TP3 4 Connect a voltmeter between battery plus TP3 and analog ground TP4 5 Turn on the power supply and adjust it for 9 V 6 Turn on the kVp Meter The voltmeter should read between 2 4 V and 3 2 V 7 Slowly decrease the power supply voltage until the voltage at the test point starts to drop between 6 5 V and 7 5 V 8 Slowly increase the power supply until the voltage across the test points just r...

Page 24: ...on 5 2 Adjustments 80 150 kVp Calibration Adjustments R6 d R3 Low Battery Threshold Adjustment R25 Three Phase Adjustments R19 and R60 R TP1 R60 TP1 R R TP3 TP2 Below Batter TP8 R33 TP7 TP4 TP1 TP9 TP5 R19 R Figure 5 1 Adjustment and Test Point Locations ...

Page 25: ...gle 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 a...

Page 26: ...0 kVp 50 mA and 0 3 seconds 9 Make an exposure NOTE If the C D decimal point is flashing indicating that the intensity of the exposure is too high decrease the mA or increase the FDD and repeat the exposure 10 Adjust R3 until the display reads 140 kVp 11 Repeat Steps 5 through 10 until the readings are accurate ...

Page 27: ...ollowing procedure to gain access to the circuit board components and test points NOTE Refer to Figure 5 1 see Section 5 Calibration and Adjustments for adjustment and test point locations 1 Remove the two screws from the case bottom 2 Carefully lift the top cover to expose the circuit board 3 If necessary remove the four screws which attach the slide filter to the circuit board to gain access to ...

Page 28: ...time NOTE Data with a kVp test cassette may be useful Be sure to note positioning error and film usage when using the cassette 4 Record all parameters of the measurement including geometry cable connections tube ID generator ID divider and kVp Meter waveform oscilloscope pictures oscilloscope and voltmeter ID 5 Periodically every 6 months or when a serious discrepancy occurs repeat Steps 1 through...

Page 29: ...ges Equipment recommended for troubleshooting the kVp Meter includes 1 A digital voltmeter Fluke Model 77 or equivalent 2 A storage oscilloscope Tektronix Model 2430 or equivalent Use the following procedure 1 Connect the DVM negative lead to TP4 circuit ground NOTE NOTE All measurements will be made with reference to TP4 2 Apply power to the unit under test 3 Test for the voltages listed in Table...

Page 30: ...Victoreen 07 494 Operators Manual 6 4 CH1 TP1 CH2 TP8 Setup Single phase x ray machine 74 5 kVp 300 mA 28 SDD CH1 1V CH2 1V A 20ms 328mV CH1 CH1gnd CH2gnd CH1 CH2 Figure 6 2 Oscilloscope Waveform A ...

Page 31: ...ce and Troubleshooting Verifying Supply Voltages 6 5 CH1 TP1 CH2 TP9 Setup Single phase x ray machine 74 2 kVp 300 mA 28 SDD CH1 1V A 20ms 563mV CH1 CH2 1V CH1gnd CH2gnd CH1 CH2 Figure 6 3 Oscilloscope Waveform B ...

Page 32: ...Victoreen 07 494 Operators Manual 6 6 CH1 TP1 CH2 TP2 Setup Single phase x ray machine 75 5 kVp 300 mA 28 SDD CH1 1V A 20ms 563mV CH2 CH2 1V CH1gnd CH2gnd CH1 CH2 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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