JPS6058407B2 - radiation thermometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation thermometer that measures the temperature of an object by using radiant energy from the object.

Traditionally, radiation thermometers include monochromatic thermometers that measure object temperature from the amount of radiant energy from the object being measured, and two-color thermometers that measure object temperature from the ratio of spectral radiant energy of two different wavelengths. .

However, the electrical signals obtained in both cases have a non-linear relationship with temperature, and a linearizer is required to linearize this, and if you want to display digitally, analog signal processing is required. -D converter is required, which causes the problem that the circuit becomes complicated and expensive. In view of the above points, it is an object of the present invention to provide a radiation thermometer which uses a simple circuit, does not require the provision of a linearizer, and can also obtain a digital output.

FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention.

In the figure, 1 is the object to be measured, 2 is a condenser lens that collects the radiant energy from the object to be measured, 3 is a detector that receives the radiant energy collected by the condenser lens 2 and converts it into an electrical signal, 4 5 is an amplifier that amplifies the output signal of the detector 3 with a predetermined amplification degree α, and 5 compares the output signal Ec of the amplifier 4 and the potential of a capacitor C of a time constant circuit 6 consisting of a parallel connection of a capacitor C) and a resistor R. A comparator, 7 is a pulse generator such as a monostable multivibrator that uses the output of the comparator 5 as a pulse signal, 8 is an integrator that integrates the pulse signal of the pulse generator 7 to obtain an analog signal voltage, and 91 is an integrator. 92 is a second output terminal for taking out the digital output signal of the pulse generator 7; 51 is for charging the capacitor C of the time constant circuit 6 with voltage Moo; first switch means, 52
is a second switch means for discharging the electric charge stored in the capacitor C via the resistor R, and these first and second switch means 5, 50 are connected to the output signal of the comparator 5 or the pulse generator 7. The intersection is obtained by the output signal of . On the other hand, according to Wien's equation, the radiant energy E(λ, T) at wavelength λ and temperature T is expressed as emissivity ε″.

This is the output of detector 3, and the output multiplied by α by amplifier 4 is E
If it is c, then it becomes.

Substituting equation (5) into equation (3) becomes.

From this, Enha ÷ engineering k - - 0 xT-KC, which is Solving for 1/T, becomes.

If α is chosen so that εαC1λ−5/EO=1, then

If the frequency when oscillating in a busy period is Fc, then (8
) formula becomes.

In other words, the temperature T and the number of cycles Fc are proportional, and by measuring the frequency Fc, the temperature of the object to be measured can be directly measured. As described above, the present invention compares the radiant energy signal from the object to be measured with the discharge output of the time constant circuit to extract an oscillation pulse signal, thereby measuring the temperature of the object to be measured. It's a thermometer. Therefore, since the oscillation pulse signal is directly proportional to the temperature, by using this pulse signal for measurement, there is no need for a special linearizer, and the circuit can be greatly simplified, resulting in high density and high reliability. Since the measurement signal can be obtained as a direct cultivation digital signal of -V, an A-D converter is not required, and digital display and external output are easy.

Further, the amplifier 4 has a function of correcting emissivity.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of the present invention, and FIG.
The figure is a waveform explanatory diagram. 1...Object to be measured, 3...Detector, 4
...Amplifier, 5...Comparator, 6...
...Time constant circuit, C...Capacitor.

Claims (1)

[Claims] 1. A detector that receives radiation energy from the object to be measured and converts it into an electrical signal, an amplifier that amplifies the output of this detector, and a time constant circuit that compares the output of this amplifier with the output of a time constant circuit. a comparator that generates an output signal when the discharge output of the comparator becomes smaller than the amplifier output, and switch means that charges the capacitor of the time constant circuit when the output signal of the comparator is generated, A radiation thermometer characterized in that the temperature of the object to be measured is measured from the obtained pulse signal.