Fluke Biomedical 07-492 - Manual (Page 13)

Battery Installation and Setup
Determining mAs Requirements
3
3-3
Typically, the largest apparent variation in mAs requirements will be due to a kVp error. If doubling the
mAs fails to produce a result, increase the kVp setting (or decrease the FDD) until a result is achieved.
Figure 3-2. Minimum Requirements (mA vs. kVp)
3.5 Initial and Periodic Operation Checks
Generally it is not easy to verify the accuracy of the kVp meter in normal field usage. If care is taken,
either of the methods outlined in the following sections can be used to verify performance of the meter.
Both methods discussed require a careful collection of installation data and periodic measurement of that
data.
3.6 Voltage Divider Method
Use the following procedure to perform initial and periodic operation checks of the kVp meter if an x-ray
voltage divider is available:
1. Choose two x-ray systems suited for the test, preferably two different systems, i.e. three phase vs.
one phase, falling load vs. not, etc. Choosing two dissimilar x-ray machines for the check reduces
the possibility of systematic errors.
2. Make comparative measurements of the x-ray systems using the voltage divider and the kVp meter.
22 24 26 28 30 32 34 36 38 40 42 44
kVp
mA
1
2
3
4
5
7
2
3
4
5
7
10
100
2
3
4
5
7
1000
Digital kVp Meter:
Typical single phase mA Requirements
May vary on different machines
FDD = 40 cm
80 cm
60 cm