Fluke Biomedical 940-513 - Manual (Page 5)

Model 940-513
Operators Manual
1-1
Section 1
General Information
1.1 Product Description
This manual outlines the procedures required for installation, operation and maintenance of the Model
940-515 Off-Line Sampler. The Model 940-513 is an off-line, single channel sampler suitable for
monitoring accident range radioactive gases. The sampler is only used with the Model 943-27-31
Current Mode Beta Scintillation Detector and radioactive check source part number 841A-123-50. The
Model 943-27-31 detector and 841A-123-50 check source are described in separate manuals. Refer to
Figure 1-1 for a general view of the sampler and Appendix A for assembly and dimensional drawings.
The sampler consists of a weldment, a detector end cap and a Gas chamber end cap. The sampler
weldment provides three (3) inches of 4 pi lead shielding around a sensitive volume and provides
inlet/outlet connections to the ample volume. Tube stubs with a ¼ inch OD are provided for connecting
the sample volume to other sampling system components (e.g. a vacuum pump, inlet filters, isolation
valves, etc.).
The detector end cap provides a means to remove and install the detector and to shield the rear of the
detector from ambient background radiation.
The Gas chamber cap provides access to the sample volume for cleaning and shields the sample volume
from ambient background radiation. The Gas chamber cap also houses the solenoid assembly used to
position a radioactive check source in view of the beta sensitive scintillation detector. The radioactive
check source available is a 100 microCurie Strontium 90 source capsule.
The Gas chamber plug is attached to the Gas chamber cap. The Gas chamber plug provides a pressure
tight seal (10 psig) for the sample volume and provided access to the sample volume for cleaning or
decontamination.
1.2 Specifications:
The following technical specifications apply to the Model 940-513 Sampler:
Dimensions ( H x W x L):
11.5 x 11.5 x 21 inches
(29.2 x 29.2 x 53.3 cm)
Weight: Approximately 500 lbs (227 kg)
Shielding: 4 pi, 3 in Lead
Inlet Diameter: ¼ inch O.D. Stn Stl tubing
Outlet Diameter: ¼ inch O.D. Stn Stl tubing
Effective Chamber Volume: Approximately 11cc
Pressure Limit: 10 psig
High Voltage Cable: Detector High Voltage cable exits the detector cap
assembly for termination at the detector preamplifier
Signal Voltage Cable: Detector Signal Voltage cable exits the detector cap
assembly for termination at the detector preamplifier
Check Source: A 100 microCurie, Sr-90 source and rotary solenoid are
located in the Gas chamber cap. Entry for the solenoid
control wiring is provided via a ½ in NPT threaded port
in the gas chamber cap.