JPH0623708B2 - Method and apparatus for measuring alcohol concentration - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus suitable for measuring the alcohol concentration in a fermentation liquor in brewing food such as alcoholic beverages, soy sauce, and vinegar.

[Conventional technology]

Conventionally, the alcohol concentration in the brewing industry has been measured by a floating method or an oxidation method as disclosed in JP-A-60-107557 at a constant interval to change the feed rate of the fermentation stock solution. .

[Problems to be Solved by the Invention] However, in the above method, it took time to obtain the measurement result, it was not possible to appropriately deal with the fermentation state which sometimes changes, and it was difficult to obtain a homogeneous product. . In addition, although a method using an enzyme sensor has been recently developed, it has a drawback that it is expensive and has a short enzyme life.

Therefore, an object of the present invention is to provide a method and apparatus for continuously measuring the alcohol concentration in a fermentation liquor with high accuracy and economically.

[Means for solving problems]

To achieve the above object, the alcohol concentration measuring method according to the first aspect of the present invention provides a gas-sensitive semiconductor chip having electrodes inside a sintered body containing SnO ₂ as a main component, a holder having a waterproof structure having a volatile gas permeable film. A semiconductor sensor having a measurement cell of a waterproof structure fixed therein, disposed in a carrier liquid kept at a constant temperature, after diluting a measurement liquid such as a fermentation liquid to a predetermined concentration with the carrier liquid, The measuring device of the second invention is characterized in that an electric signal which is an output of the semiconductor sensor is supplied to a measuring cell and is amplified by an amplifier.
A semiconductor in which a gas-sensitive semiconductor chip having an electrode inside a sintered body containing nO ₂ as a main component is installed in a waterproof holder having a volatile gas permeable film, and a waterproof measuring cell is fixedly mounted on the holder. A sensor is provided in a carrier liquid tank equipped with an electric heater for holding the carrier liquid at a predetermined temperature, and a fermentation liquid supply pump and a diluent liquid supply for diluting the fermentation liquid to be measured with the carrier liquid and supplying it to the measurement cell. A pump and an amplifier for amplifying the output of the semiconductor sensor are provided.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a flow sheet diagram of the alcohol concentration measuring apparatus of the present invention. In the carrier liquid tank 1, a liquid level sensor 2 for holding the carrier liquid at a predetermined level, and a liquid level sensor for holding the carrier liquid at a constant temperature are provided. A temperature control device 5 having a temperature sensor 3 and an electric heater 4 and a semiconductor sensor 6 for measuring alcohol concentration are provided.

A measurement cell 7 having a waterproof structure is fixed to the lower part of the semiconductor sensor 6, and a pipe 9 of a diluent supply pump 8 for supplying a carrier solution for diluting the fermentation solution is connected to the measurement cell 7. A pipe 11 of the fermentation liquid supply pump 10 is provided in the pipe 9,
Air pump 1 for rapidly removing the liquid in the measuring cell 7
2 is connected to the pipe 13, and the measuring cell 7
A pipe 14 for discharging the measurement liquid is connected to the.

In addition, as shown in FIGS. 2 to 4, the semiconductor sensor 6 has a sensor cap 16 having a protective cap 17 attached to a lower end opening of a holder 15 having a waterproof structure. The cell 7 is fixed.

In the sensor cell 16, the gas-sensitive semiconductor chip 19 is provided in the chip chamber 18, and the lower surface of the chip chamber 18 is
The gas-sensitive semiconductor chip 19 is covered with a volatile gas permeable film 20 provided close to the gas-sensitive semiconductor chip 19.
A temperature sensor chip resistor 21, a heater coil 22 and an electrode 23 are built in the sintered body containing SnO ₂ as a main component.

Further, the sensor cell 16 is connected to the operational amplifier 25 provided outside the semiconductor sensor 6 via the cell socket 24 of the holder 15, and further amplifies the electric signal of the semiconductor sensor 6 to display it on a meter or the like. Is connected to the output terminal 26.

Next, a method of measuring the alcohol concentration by the measuring device configured as described above will be explained. For example, tap water as a carrier liquid is put in the carrier liquid tank 1 and heated by the electric heater 4 to a constant temperature of about 30 ° C. The measuring cell 7 of the semiconductor sensor 6 is held, and the diluent supply pump 8 and the fermentation solution supply pump 1
0 and actuate the measurement liquid such as fermentation liquid to 10
It is diluted to a predetermined concentration of about 30 times and supplied.

In the semiconductor sensor 6, the volatile gas permeable film 20 prevents the diluent from entering the chip chamber 18, and the vapor corresponding to the alcohol concentration in the diluent diffuses into the chip chamber 18, and the vapor is transferred to the gas-sensitive semiconductor chip. It is detected at 19, and the electric signal is amplified by the amplifier 25 to display the alcohol concentration in the measurement liquid on a meter or the like.

Also, when performing automatic control of fermentation, such as controlling the feed rate of raw materials to the fermenter depending on the alcohol concentration state,
Information may be obtained by connecting to the computer from the output terminal 26.

When measuring another liquid, the air pump 12 is operated to rapidly remove the solution in the measuring cell 7, and the state of the diluting liquid, that is, the water vapor is initially set to 0 point.

FIG. 5 shows the results of measuring various kinds of measuring liquids by the above measuring device. First, the aqueous ethanol solutions A1, A2, A3, A4, A5 having a predetermined concentration were measured and the respective outputs were plotted. did. Next, when each measurement liquid such as beer was measured using this as a standard, the respective alcohol concentrations were beer = 4.30%, vinegar = 2.0.
%, Sake (4-fold dilution) = 3.30%, soy sauce = 1.55
%, Brandy (10-fold dilution) = 3.46% was obtained. It was found that these values were sufficiently reliable, with almost no difference from the measurement results obtained by the conventional method.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the alcohol concentration measuring method and the apparatus according to the present invention have a waterproof structure in which a gas-sensitive semiconductor chip having electrodes inside a sintered body containing SnO ₂ as a main component has a volatile gas permeable film. A semiconductor sensor having a measurement cell of a waterproof structure fixed therein, disposed in a carrier liquid kept at a constant temperature, after diluting a measurement liquid such as a fermentation liquid to a predetermined concentration with the carrier liquid, Since it is supplied to the measurement cell and the electric signal which is the output of the semiconductor sensor is amplified by the amplifier, the measurement result can be continuously obtained quickly and the fermentation can be easily managed. It can be easily installed and used for automatic fermentation control, and is inexpensive and easy to maintain. Furthermore, since the diluted measurement liquid is measured, highly accurate data can be obtained without being affected by other aroma components and the like.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a flow sheet diagram of an alcohol concentration measuring device, FIG. 2 is a partial sectional front view of a semiconductor sensor, and FIG. 3 is a sectional view of a main part of the semiconductor sensor. FIG. 4 is a circuit diagram of the semiconductor sensor, and FIG. 5 is a graph showing experimental results. 1 ... Carrier liquid tank, 2 ... Electric heater, 6 ... Semiconductor sensor, 7 ... Measuring cell, 8 ... Diluent supply pump, 10
…… Fermentation liquid supply pump, 15 …… Holder, 19 …… Gas sensitive semiconductor sensor, 20 …… Volatile gas permeable membrane, 23
...... Electrode, 25 …… Amplifier

Front Page Continuation (72) Inventor Nobuyuki Kawase 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya-shi, Aichi Japan Vehicle Manufacturing Co., Ltd. (72) Inventor Takahiko Yoshida 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya-shi Japan Vehicle Manufacturing Co., Ltd. (72) Inventor Yoshiaki Shibata 53, Shinotsuka Wakamiya, Kozakai-cho, Takai-gun, Aichi Prefecture Sanbishi Co., Ltd. (72) Inventor Tadahiko Inukai 1-2-7 Nishiki, Naka-ku, Nagoya-shi, Aichi Prefecture Nono Pharmaceutical Co., Ltd. (56) Reference JP-A-57-17848 (JP, A) Actual development 59-109954 (JP, U) Actual development 61-206860 (JP, U)

Claims (2)

[Claims] 1. A gas-sensing semiconductor chip having an electrode inside a sintered body containing SnO ₂ as a main component is mounted in a holder having a waterproof structure having a volatile gas permeable film, and a waterproof measuring cell is provided therein. The solid-state semiconductor sensor is placed in a carrier liquid held at a constant temperature, and the measurement liquid such as a fermentation liquid is diluted to a predetermined concentration with the carrier liquid, and then supplied to the measurement cell, and the output of the semiconductor sensor The method for measuring alcohol concentration is characterized in that the electric signal is obtained by amplifying with an amplifier. 2. A gas sensitive semiconductor chip having an electrode inside a sintered body containing SnO ₂ as a main component is provided in a waterproof holder having a volatile gas permeable film, and a waterproof measuring cell is provided therein. The solid-state semiconductor sensor is installed in the carrier liquid tank equipped with an electric heater that holds the carrier liquid at a predetermined temperature, and the fermentation liquid is supplied to the measurement cell diluted in the previous period with the carrier liquid to be measured. An alcohol concentration measuring device comprising a pump, a diluent supply pump, and an amplifier for amplifying the output of the semiconductor sensor.