Fluke Biomedical 35080B - Manual (Page 45)

Low Range Filter Pack Option (38237)
Introduction
9
9-1
Section 9
Low Range Filter Pack Option (38237)
9.1 Introduction
The Low Range Filter Pack (38237) is optimized for measurements in the 30-kVp to 90-kVp range. It can
be used to make measurements below the 50-kVp lower limit of the Wide Range Filter Pack (37617) and
Mobile Filter Pack Plus (37946) on x-ray generators with settings below 50 kVp. The Low Range Filter
Pack (38237) will typically operate at lower mA settings, making it useful in taking measurements difficult
to obtain with either the Wide Range Filter Pack (37617) or Mobile Filter Pack Plus (38237) at the lower
end of their kVp operating range.
9.2 Specifications
Range
30 kVp to 90 kVp
Sensitivity
0.1 V/10 kV
Cal
0.150 V
Zero
26 kV
Cal
41 kV
Accuracy
± 2%, exclusive of linearity and filtration effects
Minimum Anode Current for less than ± 1 kV effect
Typical at 22 inches with a 3 phase x-ray generator, 3 mA from 90 kVp down to 50 kVp, increasing to
10 mA @ 40 kVp and 30 mA @ 30 kVp.
9.3 Theory of Operation
The Low Range Filter Pack (38237) operates in a manner similar to the operation of the Wide Range
Filter Pack (37617) described in Section 3. The thickness and composition of the filters have been
optimized for operation over the 30 kVp to 90-kVp range in the Low Range Filter Pack (38237). The filter
differences cause the different Cal and Zero voltages specified, and require different correction curves
shown later in this section.