SU107045A2 - Instrument measuring the average temperature - Google Patents

Description

A schematic of the described device, which is an improved tool, for determining the average temperature value proposed in the ed. St. .NO 90247, shown in the drawing.

When the anode voltage is turned on, the thyratron 72 is ignited. Having cut it and the pulse counter C, a current pulse passes, which charges the capacitor C almost to the full voltage of the anode feed. In this case, the potential of the cathode of the thyratron becomes much greater than the potential of its grid, and the thyratron goes out. The capacitor discharge through the pentode A begins. The duration of the discharge depends on the anode current of the lamp ..7i, the value of which is controlled by the sensor R t temperature. As capacitor C is discharged, the potential of the cathode of the thyratron decreases, while the potential of the anode remains constant.

When the potential difference between the anode and the cathode becomes equal to the ignition potential Of, the capacitor C is again charged through the thyratron prior to the initial voltage. The frequency / repetition of the charge cycles of the capacitor depends on the rate of discharge of the latter through the lamp //, i.e., ultimately, on the temperature of the sensor RT.

The number of pulses N counted by the counter over time is determined by the formula:

If / is directly proportional to the measured temperature, then the readings of the pulse counter N are proportional to the average temperature of the thermal resistance during the time interval,. Time is measured by an electronic time relay, the circuit of which is given in the ed. St. No. 90247.

In the scheme given in auth. No. 90247, capacitor C is charged through the pentode and discharged pulsed through a thyratron, the instability of the ignition potential of which can lead to large measurement errors. In the device described, the capacitor is charged at full pulse

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