JP2013142627A - Moisture meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce infrared transmission amount from a sample observation window, to improve heat efficiency, and to reduce temperature unevenness.SOLUTION: In a heat drying moisture meter, in order to reduce infrared transmission from a sample observation window in a chamber 108, a reflection panel having an opening which can maintain visibility of a sample or a filter which reflects infrared ray on the sample observation window and transmits visible light is provided, so that temperature unevenness is reduced and heat efficiency is improved.

Description

  The present invention relates to a heat-drying type moisture meter for measuring a moisture content, a volatile content rate of a sample, or a mass reduction amount due to drying.

  Moisture meters are used in a wide range of fields such as chemistry, medicines, and foods, and samples to be measured are various, such as solids, liquids, gases, and granular materials. The method of measuring the amount of moisture is also the method of measuring the amount of light absorbed by the sample, the method of measuring the electrical resistance and capacitance of the sample, placing the sample in a vacuum atmosphere, drying it, and drying There are many methods for measuring the mass before and after. Among these, the heat-drying moisture meter, which evaporates the moisture in the sample by heating and measures the mass change of the sample before and after heating, can handle many types of samples and is relatively inexpensive to manufacture. It has the following features.

The invention introduced in Patent Document 1 relates to temperature detection on a weighing pan in a heat-drying moisture meter.
Hereinafter, the heat-drying moisture meter is referred to as a “moisture meter”.

JP 2003-302324 A "Filter", [online], Optline Inc., [Searched on November 20, 2011], Internet "URL: http://www.opto-line.co.jp/en/filter/filter_coldhot.html"

  FIG. 2 shows a cross section of a conventional moisture meter. That is, the heater 206 and the reflecting plate 205 that reflects the infrared rays from the heater 206 are used as means for heating the sample, and the weighing pan 209 on which the sample is placed and the mass are measured as means for measuring mass change before and after heating. The mass measuring unit 210 is configured.

  The sample is placed on the weighing pan 209 and heated, but if the heating is not sufficient, the moisture in the sample cannot be completely evaporated and remains. Further, if the heating is over, the sample surface may be burnt. If the sample is not heated uniformly, it causes a measurement error such that the moisture evaporates only a part of the sample. For this reason, a space (chamber) 208 for heating the heat from the heating means to the entire sample on the weighing pan is provided. An observation window 203 is provided for visually observing the heating condition of the sample in the chamber 208.

During warming, the chamber 208 becomes quite hot. In order to protect the operator from these high-temperature bodies, an apparatus cover 207 provided with an observation window 202 is covered.
The two types of observation windows 202 and 203 are arranged so as not to interfere with the observation of the sample. These observation windows are referred to as an outer observation window and an inner observation window, respectively.
Heating requires visual observation from the sample observation window as well as temperature measurement in the chamber. However, heat radiation from the observation window, particularly heat radiation from the inner observation window, causes temperature unevenness in the chamber and increases the heating efficiency. Bring about a decline.

  The problem to be solved by the present invention is to prevent temperature unevenness due to heat radiation from the sample observation window and to increase the heating efficiency.

The present invention is configured in view of the above-described problems, and means for heating and drying a sample placed on a weighing pan of a mass measuring unit with a heat source, a sample mass before heating, and a mass after heating drying, In the apparatus for measuring the moisture content of the sample, a reflection plate having an opening capable of maintaining visibility for observation in the observation window for observing the sample, or a filter that reflects infrared light and transmits visible light is provided. It is a moisture meter characterized by this.
The reflector is preferably a plate-like reflector provided with perforations in a grid pattern, or a string-like reflector knitted coarsely and provided with an opening in a grid pattern.
The reflection plate may be an aluminum film (a film that reflects both visible light and infrared light with high efficiency) deposited on a heat-resistant glass in a lattice shape or a half mirror shape.
Further, the filter may be a heat resistant glass coated with a dielectric multilayer film.

  According to the present invention, since the infrared rays radiated from the observation window are reflected and contribute to the heating, the heating effect is improved, the temperature unevenness in the chamber is reduced, the apparatus cover temperature is lowered, and the safety is improved.

The cross-sectional example of the heat drying type moisture meter which concerns on this invention is shown. The example of a cross section of the conventional heat drying type moisture meter is shown. Examples of punching metal and mesh are shown. (A) is an example of a punching metal, and (B) is an example of a mesh.

  FIG. 1 shows an example of a cross section of a moisture meter according to the present invention.

  In the moisture meter according to the present invention, a sample is placed on a weighing pan 109 in the chamber 108, and the inside of the chamber 108 is heated by the heater 106 and the reflection plate 105 that reflects infrared rays from the heater 106, thereby evaporating the moisture in the sample. After being allowed to evaporate or evaporate, the mass of the sample on the weighing pan 109 is measured by the mass measuring unit 110 provided under the chamber 108.

  Sample observation in the chamber is performed through an outer observation window 102 provided in the apparatus cover 107 and an inner observation window 103 provided with an opening in the chamber 108.

  Since the inner observation window material can withstand the temperature rise in the chamber, a heat-resistant glass material is used. However, this alone causes heat dissipation from the observation window, which hinders heating and causes temperature unevenness in the chamber.

  Therefore, a reflector or filter 104 having an opening that retains the visibility for sample observation is provided on the inside of the heat-resistant glass.

  As a suitable example of the reflecting plate, as shown in FIG. 3 (A), for example, a punching metal obtained by processing circular perforations into a grid pattern in a plate-like reflecting material, or a string-like shape as shown in FIG. 3 (B). A reflector is coarsely knitted to provide openings in a grid pattern.

  Alternatively, an aluminum film (a film that reflects both visible light and infrared light with high efficiency) may be deposited on the heat-resistant glass in a lattice shape or a half mirror shape.

  Furthermore, a similar result can be obtained with a dielectric multilayer coating filter (hot mirror) (see Non-Patent Document 1) that transmits visible light to the heat-resistant glass and reflects the infrared region.

  As described above, according to the present invention, heat radiation from the observation window is reduced, temperature unevenness is reduced and heating efficiency is increased, and heat transmitted to the apparatus cover 107 is reduced, thereby improving safety.

102 Outer observation window 103 Inner observation window 104 Reflector or filter having an opening 105 Reflector 106 Heater 107 Device cover 108 Chamber 109 Weighing pan 110 Mass measuring unit 202 Outer observation window 203 Inner observation window 205 Reflector 206 Heater 207 Device cover 208 Chamber 209 Weighing pan 210 Mass measuring unit

Claims (5)

  Observation of observing the sample in a device that measures the moisture of the sample from the means for heating and drying the sample placed on the weighing pan of the mass measuring unit, and the sample mass before heating and the mass after heating and drying A moisture meter comprising a reflector having an opening capable of maintaining visibility for observation or a filter that reflects infrared rays and transmits visible light in a window.   2. The moisture meter according to claim 1, wherein the reflecting plate is a plate-like reflecting material provided with perforations in a grid pattern.   2. The moisture meter according to claim 1, wherein the reflector is formed by coarsely braiding a string-like reflector and providing openings in a grid pattern.   2. The moisture meter according to claim 1, wherein the reflecting plate is formed by depositing an aluminum film on a heat-resistant glass in a lattice shape or a half mirror shape.   The moisture meter according to claim 1, wherein the filter is a heat-resistant glass coated with a dielectric multilayer film.

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