SU1144043A1 - Psychrometer - Google Patents

Abstract

A PSYCHROMETER containing parallel and wet mercury thermometers with transparent measuring capillaries and a device for measuring the extent of mercury levels in capillaries, characterized in that, in order to improve the accuracy and realize the possibility of automation of measurements, a part of the mercury column in the capillary thermo, meter, not less than the difference in height of the pillars of mercury when measured in dry air, is replaced with a clear liquid, above which an additional pillar of mercury with a height not a smaller height of the transparent liquid region, with the measuring capillaries placed between the illuminator and the photodetector of light, which is a device for measuring the difference in levels (L columns of dry and wet thermometers.

Description

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The invention relates to a measurement technique and is intended for meteorological research.

A known method for measuring the humidity of gases and a device for its implementation, where dry and wet thermistors are electrically heated by passing a current of equal amplitude through them and measuring the difference in heating time of these thermistors to a predetermined temperature fll.

The disadvantage of this technical solution is the difficulty of obtaining high accuracy of measurements, which is caused by finding the temperature difference after converting them into time intervals. As is known, when calculating the difference between two close values, the relative error increases significantly, therefore, to obtain a given measurement accuracy — temperature conversion accuracy — the time interval should be significantly longer.

In particular, when measuring the heating time from 20 to 200 ° C, the conversion accuracy should be 180 ° C / LT ft20 times the specified measurement accuracy, where T is the temperature difference between the ciocoro and the humid thermistors.

The closest to the technical essence of the invention is a psychrometer, which has installed at the same level and are parallel to dry and wet mercury thermometers with transparent measuring capillaries and a device for measuring the difference between the levels of mercury in the capillaries.

The drawback of the device is the complexity of the measurement process, which involves the need to read thermometers (dry and wet) twice, and, in addition, the need to refer to the psychometric table, which requires a certain amount of time, attention, and may cause errors in determining the humidity.

The purpose of the invention is to increase the accuracy and realization of the possibility of automating the measurement.

This goal is achieved by the fact that in a psychrometer that contains both dry and wet mercury thermometers with transparent measuring capillaries and instruments installed at the same level and located in parallel

The reading of the difference between the levels of mercury in the capillaries, a part of the mercury column in the capillary of a dry thermometer, is not less than the difference between the heights of the table of mercury when measured on the transducer

air, replaced with a transparent liquid, the cad of which contains an additional pillar of mercury with a height not less than the height of the transparent region

to liquids, with measuring capillaries placed between the illuminator and the photodetector of light, which is a device for measuring the difference in the levels of the posts of dry and wet thermometers.

The drawing shows a diagram of the device.

The psychrometer contains 2 mercury thermometers installed on the same level and parallel to the dry 1 and wet thermometers with transparent measuring capillaries. Part of the mercury column in the capillary of a dry thermometer is not less than the difference between the heights of the mercury columns when measured on a dry

air, replaced by a transparent liquid 3, above which an additional mercury column 4 is placed with a height not lower than the height of the transparent liquid section, and the measuring capillaries are placed between the illuminator 5 and the light photo-receiver 6, which is a device for measuring the difference in the levels of the columns of dry and wet thermometers.

The device works as follows.

The light falling on the capillary of a dry thermometer 1 passes through a section of a clear liquid (ethyl alcohol or toluene), which separates the mercury column into two parts in the thermometer, passes through the free part of the capillary of the wet thermometer

5 and illuminates the photodetector 6. At a humidity of 100%, i.e. when both thermometers have the same temperature, the photodetector is not illuminated. When decreasing moisture increases

0 is the difference between the temperatures of dry and wet thermometers, which leads to the appearance of an optical window, through which the light reaches the photodetector, and, the lower the humidity, the

5 wider window h the wider the illuminated area of the photodetector.

Thus, the device allows to increase the measurement accuracy and

Claims (1)

A PSYCHROMETER containing dry and wet mercury thermometers installed on the same level and arranged in parallel with transparent measuring capillaries and a device for counting the difference in the levels of mercury in the capillaries, characterized in that, in order to increase the accuracy and make automation possible, part of the mercury column in the dry capillary thermometer, not less than the difference in height of the mercury columns when measured in dry air, is replaced by a transparent liquid, over which an additional mercury column is placed with a height not smaller height section of a transparent liquid, and the measuring capillaries are placed between the illuminator and the photodetector of light, which is a device for counting the difference in the levels of the columns of dry and wet thermometers. SU, „P 44043