Filter
Top Products
Introduction
Specifications
1
1-3
Relative Humidity (Storage): 0 to 95% (non-
condensation)
Relative Humidity (Operating): 0 to 90% (non-
condensation)
Irradiation: 3.5 to 1 x 10
3
Rads @ 60°C integrated over
40 years life.
Mounting 876-1-55, Rack Chassis
Available Options (consult factory) 876A-100: Readout, for use with digital systems
Outputs: 0
- 100 mV
0
- 50 mV
0
- 10 mV
0
- 5 V
Figure 1-2 illustrates the typical energy response for the detector, Figure 1-3 illustrates typical linearity for
the detector and Figure 1-4 illustrates radiation input versus meter reading.
1.3 Equipment Overview
High-Range Containment Monitor Detector (877-1)
The high-range containment monitor detector is an ion chamber detector that has the appearance of a
six-inch diameter domed cylinder about seven inches long. Inside the cylinder are two flange-mounted
electrodes consisting of 31 flat, disk-shaped plates, each about four inches in diameter, stacked, and
mounted on disk rods. The assembly has the appearance of a large air capacitor. The mounting posts are
attached to the mounting flange through insulating spacers, so the flange and housing will be neutral with
respect to the charges applied to the electrodes.
The whole assembly is covered by the six-inch diameter housing which contacts only the neutral
mounting flange. The mounting flange is pierced by three holes. One hole supports the exhaust tube used
for exhausting and back filling the chamber. The other two support two 2-pin connectors, one for each
electrode. One pin in each pair is connected to the neutral mounting flange. When the coaxial signal
cable is connected to this connector, the cable shield is connected to the neutral pin.
The entire chamber is filled with a mixture of helium and nitrogen at atmospheric pressure and sealed.
For further information refer to Section 4, Functional Description.
Readout Module (876A-1)
The 876A-1 Readout Module is designed to give an indication, on an analog meter, of radiation levels
within the containment area. The readout is composed of an analog meter, indicator lights and operating
switches. The meter has a range of 1 to 10
7
R/h and is controlled by an eight position rotary switch. The
readout is mounted in the 876-1-55 Rack Chassis located in the control room.
For further information refer to Section 4, Functional Description.
Rack Chassis (876-1-55)
The 876-1-55 Rack Chassis permits mounting of two readout modules or one readout module and one
optical isolator in a 19-inch wide RETMA equipment rack. The panel height is 5.21 inches.
For further information refer to applicable drawing located in Appendix C.