JP3164178B2 - Moisture value correction method of resistance type single grain moisture meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance type grain moisture meter and, more particularly, to a method for correcting a moisture value which changes due to insulation deterioration between electrode rolls for measuring the moisture value of a grain.

[0002]

2. Description of the Related Art Conventionally, in a resistance grain moisture meter,
Correction methods and devices that take into account changes in electrical characteristics due to temperature,
In addition, there are many known techniques such as those that attempt to measure the measurement range in one range, but there is no known example that deals with insulation deterioration between electrodes sandwiching grain, and almost all mechanical insulation measures are taken. Met.

[0003]

SUMMARY OF THE INVENTION A resistance-type moisture meter for a grain, which measures a moisture content of a grain by rotating a pair of electrode rolls and sandwiching the grain between the electrode rolls, is known. In most cases, the operating environment is a place with a lot of dust and moisture, and the insulation between the mechanically insulated electrodes may be deteriorated due to dust, moisture and the like due to long-term use. This insulation deterioration has the same effect as connecting another resistance material to the pair of electrodes in parallel.

[0004] Furthermore, the insulation degradation, when less insulation deterioration initial dust and moisture is still resistance is infinite, the inter-electrode
It does not affect the moisture value of the grain measured with the grain in between, but due to aging, a lot of dust adheres between the electrodes and may cause insulation deterioration of about 500 MΩ especially in a humid day measurement. . When the insulation deteriorates to this extent, it depends on the equipment, but the one having a water content of about 15% is usually 16%.
% Is displayed, and the grain is over-dried for producers who dry the grain by relying on the moisture meter which has become such an electrode whose insulation has deteriorated.

[0005] This phenomenon is not out distinct difference as accidental often to occur, yet extremely 5% Toka 10% depending on the conditions of use environment, for example say a day high the humidity such as Less noticeable during use. Further, there is a difference in how to handle the apparatus depending on the user, and at present, not all the users perform the detailed check before use. Furthermore, some devices have taken safety measures so that they cannot be used if there is an output voltage due to insulation deterioration when there is no grain, and these devices have been disabled.

[0006] From the above, the applicant of the present invention has always obtained a correct grain moisture content by a moisture value correction method for automatically correcting errors in measured values due to the influence of insulation deterioration between electrode rolls caused by aging. The technical issue is to provide a resistance type single grain moisture meter capable of measuring water content.

[0007]

In order to solve the above-mentioned problems, the present applicant supplies grains one by one between a pair of electrode rolls provided at an arbitrary interval, and feeds the grains between the electrodes. In a resistive single grain moisture meter for measuring the output voltage obtained by sandwiching the grains to determine the moisture content of the grains, the grain is inter-electrode by a predetermined relational expression between the output voltage and the resistance value between the electrodes. the resistance value R _P between the electrodes at that time from the sandwiched therebetween resulting output voltage,
Grains is calculated and a resistance value R ₁ between the electrodes at that time from the output voltage obtained without sandwiched between electrodes, the resistance value R _P and the resistance value R ₁ and the resistance relationship 1 / R P _{= (1} / R ₂ ) + (1
/ From R ₁₎ and to calculate the resistance value R _2, the output voltage obtained by the said resistance R ₂ and the predetermined relationship, as an output voltage to determine the true moisture content of the grain, resistive single The method was used to correct the moisture value of the grain moisture meter. Further resistance R ₁ between the obtained without pinch the grain electrode, before and after sandwiching the grain between the electrodes, and the average value of the resistance value between the electrodes when no across the grain between electrodes . Also, put the grain between the electrodes
When there is a predetermined difference in resistance between the electrodes before and after
Incorrect measurement.

[0008]

[Action] Originally, the resistance value of a grain sandwiched between a pair of electrodes
Current flows according to the output voltage to determine the moisture content of the kernel.
But error may occur due to insulation deterioration between electrodes
In the case , the deterioration of the insulation between the electrodes progresses , and the current flows through the portion where the insulation is deteriorated, that is, the portion not passing through the grain between the electrodes, in addition to the current. This is the same phenomenon as providing a resistor in parallel between the electrodes, and it can be seen that the resistance value between the electrodes calculated from the obtained output voltage is lower than the resistance value when the insulation does not deteriorate. This reduction in resistance between the electrodes results in an increase in current and an increase in output voltage at the measurement point.

At this time, the difference between the output voltage E and the resistance value R between the electrodes is calculated.
An example of the predetermined relational expression can be expressed as follows.

[0010]

[Equation 1] E = -a × ln (R) + b (a, b are constants) This equation 1, the resistance value between the electrodes at that time from the output voltage E _P obtained across the grain between electrodes to give R _P, also can be obtained from the output voltage E ₁ by insulation deterioration resulting in a state not to pinch the grain between the electrodes to obtain a resistance value R ₁ by insulation deterioration between the electrodes at this time. The resistance value R _P at this time, can be by parallel resistance of the resistance value R ₁ between the electrodes without passing through the grain by the resistance value R ₂ and insulation degradation between sandwiching the grain electrode. This relationship can be expressed by the following equation.

[0011]

[Formula 2] 1 / R _P = (1 / R ₁ ) + (1 / R ₂ ) By this formula 2, the resistance value R ₂ between the electrodes sandwiching the grain generated by the grain between the electrodes is originally obtained. be able to. That resistance value R ₂ is intended to refer to the resistance of the grain to be obtained by removing the resistor R ₁ minute due to insulation degradation.

By substituting the obtained resistance value R ₂ into the above equation 1, it is possible to obtain an accurate output voltage E ₂ obtained when a grain is sandwiched between the electrodes, that is, the influence of insulation deterioration is removed. it can. This method is not always required to be executed, when the output voltage E ₁ current flows due to insulation deterioration exceeds a predetermined voltage, executing when it is resistance which affects the output voltage E ₂ in other words Good.

The resistance value R ₁ is obtained by taking the average value of two resistance values R ₁ before and after the output voltage is measured with a grain sandwiched between the electrodes, thereby obtaining a more accurate insulation deterioration. Can be taken into account. Between these two resistance values
If there is a large difference, foreign matter may bite the electrode roll.
It can be determined that the
It is possible to

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a preferred embodiment of the present invention will be described. FIG. 1 shows the connection between a pair of electrode roll portions 1 of a single-grain type grain moisture meter and a logarithmic amplifier circuit 2. The output of the logarithmic amplifier circuit 2 is an output voltage E. The pair of electrode portions 1 comprises an electrode roll 3 and an electrode roll 4 which are rotatably provided at an arbitrary interval, and one of the electrode rolls 4 is connected to a pull-up power source 5. The other roll 3 is electrically connected to the input side 6 of the logarithmic amplifier 2. Actually, other components such as an electrode roll driving unit, a signal processing unit 7 for the output voltage E, and a calculating unit 8 are included, but detailed description thereof is omitted.

When grains are put between the electrode rolls 3 and 4 one by one, the output voltage E has an output waveform as shown in FIG. 2 as an example. The signal processing unit 7, pin samples the output voltage, for example, 20ms intervals - are set as the water content of the grain captures click voltage E _P. Note that the output waveform indicated by the solid line indicates the case where there is no insulation deterioration, and the output waveform indicated by the dotted line indicates the case where the insulation deterioration is affected.

FIG. 3 shows an output voltage E output when a grain is put between the electrode rolls 3 and 4 and the electrode rolls 3 and 4 are rotated to sandwich the grain. 3 shows the relationship between the resistance of the grain between the electrode rolls. The linear equation representing this relationship is shown by Equation 1 above. The insulation deterioration that is the subject of the present invention is the deterioration of the electrical insulation between the electrode rolls 3 and 4 provided at an arbitrary interval. Unless the grain is sandwiched between the electrode rolls, since an arbitrary interval is originally provided,
In normal use, the two electrode rolls are not electrically connected, but a bearing part for supporting the roll in rotation or a shear is provided.
In some cases, the same state as when a parallel resistance is virtually connected to the electrode rolls 3 and 4 may be caused due to insulation deterioration of the portion. FIG. 3 shows the effect of the insulation deterioration between the electrodes. The resistance value of this virtual parallel resistor is 100 MΩ, 20
At 0 MΩ, 600 MΩ, and 1000 MΩ, the influence on the output voltage E when each is added is shown.

In the present invention, this effect is eliminated by the following method. As shown in FIG. 4 (2), the electrode rolls 3, 4
Between a resistance value R ₂ by grain sandwiching constitute a parallel circuit of a resistance R ₁ by a virtual parallel resistance i.e. insulation degradation. The output voltage E from the logarithmic amplification circuit 2 is an output voltage E _P by the parallel circuit of the R ₁ and R _2. Also as in (1) or (3) in FIG. 4, cereal electrode b - when not sandwiched between Le becomes only the resistance value R ₁ by insulation deterioration, resistance R ₁ of the insulation deterioration
The output voltage _{E 1} according exists.

Although the output voltage E can be actually measured, the output voltage E and the resistance value R have a linear relationship as shown in FIG. 3, and E = −a × in the above [Equation 1]. ln
(R) from + b, and the resistance value _{R P} for the output voltage _{E P,}
It is possible to calculate the resistance value R ₁ for the output voltage E1. Wherein the resistance value R _P is the resistance value R ₁ as described above R
Since the resistance of the parallel circuit of the _two, also _{1 / R P = (1 /} R 1) of the above [Equation _{2] + (1 / R 2} ) by obtaining the resistance value _{R 2} by the original grain Can be.
Therefore, Substituting in the resistance value R ₂ obtained here [Formula 1], it is possible to calculate the output voltage E ₂ at this time.

The output voltage E ₂ obtained here, a cereal electrode b - obtained when sandwiched Le, an output voltage to be obtained by removing the influence of the insulation deterioration resistance R _1, the grain to be found water The output voltage is based on the rate.

[0020] Now, the output voltage E ₁ by the resistance value R ₁ of the insulation degradation is grain electrode b as in (3) in FIG. 4 (1) in FIG. 4 - output obtained when sandwiched Le _'because it can be measured, the resistance value is determined from the two output voltages R ₁ and R _1' output voltage E ₁ and the output voltage E ₁ before and after the voltage E _P and R ₁ taken an average value of the it is possible, electrode b in the case where there is a large difference between the case where the resistance value R ₁ and R _{1 '-} or it is determined that the foreign matter has been bitten Le, whereby the the measurement The data can be determined as a measurement failure.

As described above, the influence of the insulation deterioration between the electrode rolls on the measurement of the water content of the grain can be corrected by the output voltage constantly obtained in the measurement state. No components or components are required, and the implementation can be easily performed simply by changing the sampling of output voltage and data processing.

[0022]

Until now, when there is an output voltage when no grain is sandwiched between the electrode rolls, that is, when there is an output voltage due to insulation deterioration, it is regarded as abnormal and measurement is impossible, and often work is not performed. However, the present invention removes the influence of insulation deterioration and makes it possible to use it. Therefore, regardless of whether the environment is good or bad, use the electrode roll. Irrespective of the difference in handling by the aged, stable measurement of the moisture content of the grain was always possible. This makes it possible to exhibit the effects of the present invention particularly as a continuous grain moisture meter provided in a drying apparatus for continuously drying grains.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a connection between an electrode roll portion of a single grain moisture meter and a logarithmic amplifier circuit.

FIG. 2 is a diagram showing an example of a waveform of an output voltage from a logarithmic amplifier circuit of a single grain moisture meter.

FIG. 3 is a diagram showing a linear relationship between an output voltage and a resistance value of a grain between electrode rolls, and an influence of insulation deterioration between electrodes.

FIG. 4 is a diagram showing a resistance value of a grain existing between electrode rolls and a state of a parallel resistance due to deterioration of insulation between the electrodes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode roll part 2 Logarithmic amplifier circuit 3 Electrode roll 4 Electrode roll 5 Pull-up power supply 6 Input side of logarithmic amplifier circuit 7 Signal processing means 8 Operation means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-292047 (JP, A) JP-A-57-161644 (JP, A) JP-A 2-41153 (JP, U) JP-A 53-161 63288 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/00-27/24

Claims (3)

(57) [Claims] 1. A grain is supplied one by one between a pair of electrode rolls provided at an arbitrary interval, and an output voltage obtained by sandwiching the grain between the electrodes is measured to determine a moisture content of the grain. In the resistance single-grain moisture meter that determines the resistance value between the electrodes at the time from the output voltage obtained by sandwiching the grain between the electrodes by a predetermined relational expression between the output voltage and the resistance value between the electrodes R _P and
Grains is calculated and a resistance value R ₁ between the electrodes at that time from the output voltage obtained without sandwiched between electrodes, the resistance value R _P and the resistance value R ₁ and the resistance relationship 1 / R P _{= (1} / R ₁ ) + (1
/ Since R ₂₎ and to calculate the resistance value R _2, characterized in that the output voltage obtained by the said resistance R ₂ and the predetermined relationship, the output voltage to determine the true moisture content of the grain The method of correcting the moisture value of the resistance type single grain moisture meter. Wherein the resistance value R ₁ between the electrodes obtained not pinch the grain is before and after sandwiching the grain between the electrodes, the resistance value between the electrodes when no across the grain between electrodes 2. The method of claim 1, wherein the moisture value is an average value. 3. A resistance type according to claim 1, characterized in that the measurement failure when a predetermined difference in the resistance value R ₁ between the electrodes before and after sandwiching the grain is generated between the electrodes single grain Grain moisture meter Moisture correction method.