Counting rate meter

Integration. A detector that yields discrete pulses can be used as an instantaneous detector if the pulses can be averaged to form a continuous electric current, as in a counting-rate meter. These devices usually consist of a capacitor that is charged by the pulses and a re-... 

Figure 5.6. Diagram of a low-energy, high-angle electron-impact spectrometer. (A) Electron gun (B) monochromator (180° spherical electrostatic energy selector) (C) electron optics (D) scattering chamber (E) analyzer (180° spherical electrostatic energy selector) (F) electron multiplier (G) amplifier and pulse discriminator (H) count-rate meter (I) multichannel scaler (J) X Y recorder (K) digital recorder. (After Kupperman et a/.<42))...

The number of ionizations or scintillations detected by both types of detector is measured electronically and presented either as the total number of counts (a scaler) or as the number of pulses per minute (a count-rate meter)... 

The discriminator produces an output pulse with a fixed shape (generally square) and size when the input signal crosses a reference. Discriminators usually have multiple identical output signals. The logic pulses can be sent to a scaler that simply counts the number of pulses, to a count rate meter to monitor radiation rates or doses, and to a time-to-amplitude converter (TAC) to measure the relative times of arrival of two or more logic signals. 

Effluent solution from the ion exchange column is passed through an in-line alpha-detector which activates a count-rate meter and recorder outside the cell. Inside the detector/ the liquid flow is passed adjacent to a Mylar film-covered window/ which separates the liquid from the silicon diode detector. 

Field survey None Scintillation detector and count rate meter 200-500 dpm/ 100 cm" (scintillation detector) No data ANSI 1978 (ANSI Standard N323)... 

The succession of current pulses is converted into a steady current, which is measured on a meter called a counting-rate meter, calibrated in such units as counts (pulses) per second (c/s or cps). Such a circuit gives a continuous indication of x-ray intensity. 

The counting-rate meter, as its name implies, is a device which indicates the average counting rate directly without requiring, as in the scaler-timer combination, separate measurements of the number of counts and the time. It does this by a circuit which, in effect, smooths out the succession of randomly spaced pulses from the counter into a steady current, whose magnitude is proportional to the average rate of pulse production in the counter. 

Figure 8.50. Apparatus for simultaneous ETA, DTA, and TG/DTG measurements (194). A, Amplifier D, silicon surface barrier detector F. furnace 1, standard material S. sample FM. flow meter ST, flow stabilizer RM. count-rate meter.

The most common method of measuring the spinning rate is by some optical means, for example, by a photo-sensitive transistor and a light source. The spinning can be monitored on an oscilloscope in which case the quality of spinning can be kept track of as well as the speed. Alternatively, a tachometer can be constructed in a fashion analogous to counting rate meters used in nuclear physics (Elmore and Sands, 1949) and appropriately calibrated. 

The G-M counter is a simple and relatively inexpensive gas-filled tube with a count-rate meter an amplifier may also be present. The G-M detector counts alpha particles, beta particles, and gamma rays with a very thin window, counts beta particles and gamma rays with a thicker window, and counts gamma rays only with a thick shield. Alpha and beta particles interact in the gas gamma rays interact mostly in the walls, from which electrons enter the gas. The intrinsic efficiency for counting gamma rays relative to beta particles depends on the amount and type of solids surrounding the detection gas. 

In an early attempt to cover-still lower neutron intensities, the modulated ionization chamber. -was proposed. This device utilized the periodic motion of an absorber placed before the ionization chamber which resulted in a modulated signal proportional to neutrons only.r This was abandoned in favor of the fission chamber and counting rate meter which,. by reposi -tioning the fission chamber, is capable of covering a range of 10. Since this device has a long integrating time, it was felt th.at the resultant time delays would make it an unsatisfactory instrument for automatic control, and it is therefore used as an adjunct to manual control.-... 

At low levels be sure the counting-rate meter is alive. It is the only source of information at such levels, and unless its pointer gives evidence of responding to signal it would be foolhardy to attempt reactor operation. 

Logarithmic Count Rate Meter Magnet Amplifier Log N Amplifier Sigma Amplifier Neutron Chamber... 

CKBAs) count rate meters are us in low traffic or minimd entry areas. Fixed cridcalhy neutron dosimeters provide radiation momtoring in the Assembly and I sassemb Areas until all fod and target assemblies are rmoved. 

Counting Rate Meter - A device which gives a continuous indication of the average rate of ionizing events. Frequently the log of the counting rate is provided (LCRM). When plotted, the slope can be interpreted as period The log of the counting rate may be differentiated to provide a direct ihdlcatlon of period. 

LCRI-1 - (Log Count Rate Meter) - See Counting Rate Meter. 

Tha aanaora for tha low subcrltlcal level consists of two fission chambers located In tha top shield near tha reactor centerline. Tha signal In counts par second la supplied to an amplifier and a log count rata mater. Tha signal from the log rate meter la compared to two trip values. Ona causes a power setback the other actuataa the fast-rod-withdrawal Interlock. A signal from the primary count rate meter Is also Included In the fast-rod-withdrawal Interlock. 

The fission-chamber signals are fed to conventional preamplifiers, A-1 linear amplifiers, logarithmic count-rate meters and a dual-pen recorder. For initial reactor startup before gamma-neutron reactions provided a sizable neutron source, the fi.ssion-chamber output was u.scd to drive a low-range pulse counter. 

Key measurements are displayed on "full-scale recorders in the center section of the panel and include the fuel temperature, a multipoint temperature recorder, the multiarca radiation monitoring recorder, the reactor power, the logarithmic neutron-level and count-rate meter signals. 

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