SU1200202A1 - Apparatus for inspecting loading capability of linear spectrometric amplifiers - Google Patents

Abstract

A DEVICE FOR MONITORING THE LOADING ABILITY OF LINEAR SPECTROMETRIC AMPLIFIERS, containing a pulse generator, the output of which is connected via an electronic switch to the counter input of the counter, the overflow output of which is connected to the R-input of the trigger, the 5th input which is connected to the Start-up J, which is connected to the J input, which has a junction 22, which is connected to the R-input of the trigger, the J-input which is connected to the Start-up J, which has a junction that is connected to the J input, which is connected to the J start input, 5 which is connected to the J start input, which has a junction. 6ВК; Ш1ГН л. device, and the trigger output is connected to the control input of the electronic key, which is distinguished by the fact that, with a measurement time reduction circuit, a digital-to-analog converter, an analog adder, a reference voltage source, a comparator, and an indicator are entered into it, and the one-by-one outputs the counter is connected to the corresponding inputs of a digital-to-analog converter, the output of which is connected to the first terminal of the device for connecting the amplifier under test, the second terminal of which through the first input of an analog adder It is connected to the first input of the comparator, the second (L input of the last is connected to the output of the source of the reference voltage, the output of the comparator is connected to the input of the indicator, and the second input of the analog adder is connected to the counting input of the counter.

Description

The invention relates to a measurement technique-and can be used in nuclear spectroscopy to control the loading characteristics of linear spectrometric amplifiers, i.e. dependences of the energy resolution on the counting rate, which is a response of the amplifier to a hundred. T1, pulses of varying intensity, which are theoretically distributed in time, from the output of the radiation detector.

The loading capacity of a spectrometric amplifier is unambiguously characterized by the value of the limiting frequency of pulses, independent of the external generator in the form of individual dressings.

. The aim of the invention is to reduce the time required to control the loading capacity of a spectrometric amplifier by more than 50 times.

1 shows a block diagram of the device; 2 shows timing diagrams for his work. .

The device contains a trigger 1 with installation S- and R-inputs, an electronic switch 2, a generator of 3 pulses, a counter 4, a digital-to-analog converter 5, a linear amplifier 6 under test, an analog adder 7, a reference voltage source 8, a comparator 9, an indicator 10, the first 11 and second 12 terminals of the device for connecting the amplifier under test 6.

5 - trigger input 1 is connected with the Start thickness, R trigger input is connected to the overflow output of counter 4, trigger output is connected to the first input of the electronic switch 2, the input of which is connected to the output of the generator 3 and to the first input of the analog adder 7, output elec The key is connected to the counting input of the counter 4, and the serial outputs of the counter are connected to the inputs of the digital-to-analog converter 5, the output of which is connected to the input of the linear amplifier 6, the output of which is connected to the second input of the adder 7, the output of the adder is connected to one of the inputs of the comparator 9, and its second input is connected to the output of the source 8 of the reference voltage, the output of the comparator is connected to the indicator 10.

The generator 3 is configured to smoothly vary the frequency f. The counter has a binary bits and capacity (). The digital-to-analog converter has an input. Dov and at the output gives a stepwise increasing input signal Og (figure 2) with the number of stages () and the duration of each stage equal to 1 / f.

The device works as follows. . .

When an external impulse is applied to the Start at the 5th input of the trigger 1, it is switched, in which, via the electronic key, 2 pulses with a relative level. and with a frequency f (from the generator 3 output (FIG. 2), they arrive at the counting input of counter 4 and at one of the inputs of analog adder 7. An overflow pulse of counter 4, which arrives at the R input of the trigger, sets it to the initial state and stops passing pulses through the key, t

In this case, a TJg signal (Fig. 2) of a step-shaped form with a number of steps (2 -1) appears at the output of the digital-to-analogue converter 5 This signal is fed to the input of the tested amplifier 6, the output of which is fed to the first input of the adder 7 (2-1 a) unipolar pulses

with a nominal amplitude value relative to the amplitudes of the pulses applied to the second input of the analog adder 7 from the output of the generator 3. In this case, the rectangular pulses from

generator 3 and the pulses from the output of amplifier 6 must have different polarity and the same amplitude. The amplitude identity is set by smoothly adjusting the gain of the test amplifier 6 at a low pulse frequency from the generator 3 until the amplitude error signal is fully compensated.

0 compared pulses. The zero amplitude mismatch signal forms a zero baseline on the indicator 10. When increasing the frequency of the pulses from the output of the generator 3

5, the output of the amplifier 6po are pulses whose amplitude differs from the input pulses, which leads to the appearance of amplitude error signals reaching a maximum value in the region of the last pulse. An offset, baseline, and is observed. (Fig. 2) on the indicator 10. With the help of the source 8 of the reference voltage, the criterion of the maximum allowable voltage variation Tsq (Fig. 2 of the baseline relative to the zero level and increasing

200202 .4,

the frequency of the pulses of the generator 3 is determined using a comparator 9 pre (Fig. 26), with a frequency of f2 1 (Fig. 2b) which is the amplitude & U. 5, the error signal reaches the set value, which is fixed by the indicator 10. The magnitude of the limiting frequency characterizes the magnitude of the loading capacity of 10 of the amplifier under test.

V /,

%

// g

 #

 one ,

Claims (1)

DEVICE FOR MONITORING THE LOADING CAPABILITY OF LINEAR SPECTROMETRIC AMPLIFIERS, containing a pulse generator, the output of which is connected via an electronic key to the counter input of the counter, the overflow output of which is connected to the trigger R input, the 5 input of which is connected to the trigger terminal of the device, and the output an electronic key input, characterized in that, with a circuit for reducing measurement time, a digital-to-analog converter, an analog adder, a voltage reference source, a computer are introduced into it an indicator and an indicator, while the bitwise outputs of the counter are connected to the corresponding inputs of the digital-to-analog converter, the output of which is connected to the first terminal of the device for connecting the test amplifier, the second terminal of which is connected to the first input of the comparator through the first input of the analog adder, the second input of the last is connected to the source output reference voltage, the output of the comparator is connected to the input of the indicator, and the second input of the analog adder is connected to the counting input of the counter. SU „1200202>