Fluke Biomedical 35080M - Manual (Page 33)

35080M
Operators Manual
5-4
Figure
5-3. 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, set the function 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 4.4), set
the oscilloscope coupling to GND and position the trace on the bottom line. With the kVp Divider in
the ‘‘CAL’’ position, set the oscilloscope coupling to DC 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
4.4, step 6.
The CORRECTION VALUE may be either
negative or positive.
15”
Model
35080M kVp
NOTE
NOTE