Fluke Biomedical 943-25 - Manual (Page 6)

Victoreen 943-25, 943-26
Operators Manual
1-2
Response Ratio: 1:1 943-25, 943-26, 943-25T, 943-26T
10:1 943-25A, 943-26A, 943-25TA, 943-26TA
100:1 943-25B, 943-26B, 943-25TB, 943-26TB
End Window Material Mylar 943-25, 943-25A, 943-25B, 943-26, 943-26A, 943-26B
Titanium 943-25T, 943-25TA, 943-25TB, 943-26T, 943-26TA, 943-26TB
Preamplifier
Maximum Pressure 30 psi
(Face Exposure)
Rise Time < 60 ns
Input Impedance > 50 kilohms
Output Coupling AC
Voltage Gain 6 V/V
Configuration Voltage sensitive
Output Polarity Negative
Output Impedance 50 ohms
Maximum Cable Length 1500 ft
Maximum Pulse Amplitude @ -6 V
Maximum Cable Length
Dead Time Approximately 10 us @ 8 ft cable length
Maximum Count Rate 10 7
The beta detectors have been assembled with parts selected for the reliability required in a nuclear
application. Any unauthorized repairs made to the detectors utilized in nuclear applications will void the
safety-related rating. Safety-related detectors must be returned to Fluke Biomedical, Radiation
Management for authorized, qualified (ANSI 45.2.6, Skill Level II) service.
1.4 Functional Description
The Victoreen beta scintillation detector is shown in block diagram form in Figure 1-1. The detector
consists of a scintillation disc, a photomultiplier tube, a preamplifier assembly, and various interconnecting
cables connecting the detector, readout, and the detector power supply that is located at the ratemeter or
scaler module.
Figure 1-1. Block Diagram, 943 Series Beta Detector