Fluke Biomedical 35080B - Manual (Page 34)

35080B
Operators Manual
6-4
Figure
6-3. Linear Measurement Setup
2. Connect the kVp Divider output to either a storage oscilloscope or a peak-read-and-hold DMM. Set
the oscilloscope to 0.05 volts division vertical gain and the input to DC Coupled, single trace
storage mode.
The Linear Mammo Filter Pack (37351) may be
used with a peak-read-and-hold DMM for the
readout instead of or along side of the storage
oscilloscope. The device is direct-reading in kVp.
Merely multiply the display reading by 100. For
example, a voltage of 0.375 is equivalent to 37.5
kV.
3. With the Linear Mammo Filter Pack (37351) installed on the kVp Divider, move the switch to the
‘‘CAL’’ position. The voltage output should be 0.200 volts ±.003 volts (1% + 1 digit). Check CAL
voltage with a digital voltmeter or an oscilloscope with at least 0.1% accuracy. This value
corresponds to a kV reading of 20.0 kV and may be used to setup the oscilloscope. The CAL
function checks the gain of the kVp Divider. A 1% error in gain will result in a 1% error in the kVp
reading (0.3 kV at 30 kV).
4. With the same generator settings used for K-edge measurement at 29 kVp (see Section 5.4), turn
the kVp Divider to ‘‘OFF’’ and position the oscilloscope trace on the bottom line. Place the kVp
Divider in the ‘‘CAL’’ position, and the trace will move to the middle line (20 kV). The oscilloscope
with eight major vertical positions is now set to indicate a range of 0 to 40 kV. Make an exposure
and record this value separate from the K-edge reading made in Section 5.4, step 6.
The CORRECTION VALUE may be either negative
or positive.
15”
Model 35080B
kVp Divider
NOTE
NOTE