Fluke 875 manual Introduction, General Description, Specifications, Containment Monitor, Detector

Introduction

General Description 1

Section 1

Introduction

1.1 General Description

Containment Monitor 875

NOTE

The 875 Containment Monitor has been qualified for use in Nuclear Safety related applications. Qualification Test Reports, 950.301, 950.308A, and 950.310A define the parameters that have been verified by test and are available for purchase.

Containment Monitor 875 functions as an accident monitor for reactor containments, refer to Figure 1-1. It consists of the 877-1 Ion Chamber Detector that is located within the reactor containment, and the 876A-1 Readout Module that is contained in a rack in the control room. The readout module contains a power supply that provides the necessary power both for itself and the detector. The readout module is connected to the detector by two cables, a coaxial high voltage cable and a coaxial signal cable. Specifications for the detector and readout module are contained below.

1.2 Specifications

Detector 877-1

Radiation Detected	Photons above 60 keV
Range	1 R/h to 1E7 R/h
Energy Response	± 20% from 80 keV to 2 MeV
Chamber Construction	Stacked parallel plate, 316 stainless steel housing, 3
	terminal, guarded ion chamber
Saturation	>80% up to full scale on instrument
Collection Voltage	450 to 550 VDC
Current Output	7E-11 to 7E-4 Amp/R/Hr (nominal)
Chamber Capacitance	435 picofarads (nominal)
Voltage Withstand and Leakage	5E10-5 amperes @ 500 VDC between either ground and
	connector pins
Capacitance	Approximately 430 pf

1-1