JP3099470B2 - Non-contact temperature measurement system for centrifuge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type temperature measuring system for measuring the temperature of a rotating body into which a sample to be separated by a centrifuge is placed.

[0002]

2. Description of the Related Art A conventional temperature measurement of a rotating body using a thermocouple type infrared temperature sensor of a centrifuge is used as a variable when correcting the output of the temperature sensor as a reference point of a thermocouple inside the temperature sensor. Only the (cold junction) temperature was used. However, in the above-described method, even if the rotating body is completely within the field of view of the temperature sensor, since the rotating body is not a completely black body, the reflection and reflection of infrared rays from the cooling / heating bowl of the rotating body can be prevented. The influence of heat from the bowl on the temperature sensor, such as heat conduction from the bowl, cannot be ignored, and the temperature of the rotating body cannot be measured accurately. Also, Japanese Patent Application Laid-Open No. 62-1639
No. 37 discloses that an object to be measured is measured using an infrared temperature sensor.
Theoretical formula (P = K (εT ⁴ + RT) for temperature measurement
s ⁴ -To ⁴ )) is disclosed and the infrared temperature
Sensor angle, infrared temperature sensor
Filter temperature and infrared temperature sensor depending on viewing angle
By incorporating individual correction constants and ambient temperature correction constants
This shows that the temperature of the DUT can be measured more accurately.
It has been incited.

[0003]

A thermocouple-type infrared temperature sensor generally has a structure shown in FIG. 4, in which a heat-receiving portion 2 having a small heat capacity in the temperature sensor generates heat by infrared rays incident from an object to be measured. The heat is transmitted to the reference contact 4, further transmitted to the case 17, and finally radiated to the atmosphere,
A thermal equilibrium is created to create a temperature gradient inside the temperature sensor. One or more thermocouples 3, a slight temperature difference created and receiving thermal body and the reference contact of the temperature gradient voltage conversion is to shall the voltage signal of the temperature sensor. When the temperature sensor is installed in a centrifuge to measure the temperature of the rotating body, the infrared rays received by the heat receiving body include, in addition to the infrared rays emitted by the rotating body, cooling and heating of the rotating body. This includes the reflection of infrared rays from the bowl on the rotating body and the influence of wraparound. Further, the case of the temperature sensor is thermally connected to the bowl, and the heat of the bowl is transmitted to the case and the reference contact by conduction, so that the temperature sensor measures the temperature of the rotating body. Affect. Also,
Japanese Patent Application Laid-Open No. Sho 62-163937 discloses a theoretical formula (P
^{= K (εT 4 + RTs 4} -To 4)) also has been disclosed
However, only this theoretical formula takes into account the above-mentioned correction constants, etc.
Measurement cannot be performed accurately. Spirit
In order to make accurate measurements, the publication discloses the above correction constants and
Although it is suggested that fixed factors be considered, these
Requires the work of individually measuring However, in reality
Measuring them is tedious and unrealistic
Have a problem.

[0004] The object of the present invention is to rotate accurately with a simple method.
It is a Rukoto to measure the temperature of the body.

[0005]

The object of the present invention is to detect infrared rays.
Reference temperature of infrared temperature sensor that generates output signal
Temperature detection means, the reference junction temperature and the bowl temperature
Almost equal and the difference between the temperature of the rotating body and the reference junction temperature is zero
The first coefficient is obtained from the state that is not and using the first coefficient
When the difference between the bowl temperature and the reference junction temperature is not zero
By measuring the second coefficient, the temperature of the rotating body is measured.
Is achieved by

[0006]

[Action] In the temperature measurement of the upper Symbol rotating body, the individual infrared temperature
Includes sensor variations and ambient temperature variations.
By using the first and second coefficients, the temperature of the rotating body
The degree can be accurately measured.

[0007]

FIG. 1 shows an apparatus for measuring the temperature of a rotating body of a centrifuge according to one embodiment of the present invention.

The thermocouple type infrared temperature sensor 1 installed in the centrifuge receives the infrared energy 19 proportional to the fourth power of the absolute temperature TR of the rotating body 7 to the heat receiving section 2, and the temperature of the heat receiving section changes. , A temperature difference occurs between the reference junction 4 and the thermocouple 3, and the thermocouple 3 detects the temperature difference to generate a voltage signal V. A reference contact temperature sensor 5 is installed in the infrared temperature sensor to measure the absolute temperature TD of the reference contact and generate a voltage signal VD. Cooling / heating bowl 8 for the rotating body
Then, a bowl temperature sensor 9 is installed to measure the absolute temperature TE of the bowl, and a voltage signal VE is generated. V, VD, VE
Are amplified by the amplifier circuit 10 because they are weak.
The digital signal is converted by the D converter 11. The signals VD and VE are converted into the values of the absolute temperatures TD and TE, respectively, by a conversion table programmed in the ROM 13.

The voltage signal V of the thermocouple includes, in addition to the infrared energy from the rotating body, heat conduction due to contact with infrared energy from the bowl.
Becomes the following equation (1).

[0010]

(Equation 1)

In the equation (1), the first term indicates the infrared energy from the rotating body, and a is a first coefficient . The second term indicates the infrared energy from the bowl, and b is the second energy
Number . The third term shows the heat transfer from the bowl, where C is
This is the third coefficient . The temperature calculation formula for obtaining the absolute temperature TR of the rotating body from the formula (1) is the formula (2).

[0012]

(Equation 2)

The absolute temperature TR of the rotating body is obtained by programming the equation (2) in the ROM 13 and performing calculation, and the result is converted into an analog signal by a D / A converter and output. These operations are controlled by the CPU 12. The celsius temperature of the rotating body can be obtained by subtracting 273 from the absolute temperature TR. FIG. 2 shows an example of mounting the infrared temperature sensor on the centrifuge. The rotating body rotated at a high speed by the drive unit 15 is heated and heated by the bowl whose temperature is controlled by the electronic cooling element 16.
Cooling takes place. FIG. 3 shows one means for obtaining the coefficients a, b, and c of the equation (1). The ambient temperature of the centrifuge is uniform and the absolute temperature T of the reference junction in the infrared temperature sensor
In a state in which the rotating body having a large temperature difference between D and the absolute temperature TE of the bowl and the absolute temperature TD of the reference contact is large (A in FIG. 3), Second
The third term becomes 0, and the coefficient a is determined from the voltage signal V, the absolute temperature TR of the rotating body, and the absolute temperature TD of the reference contact. After the state a, the thermoelectric cooler is operated, and when the difference between the absolute temperature TD of the reference contact and the absolute temperature TE of the bowl is large (B in FIG. 3), the infrared transmitting filter 1 of FIG.
8 and cut off the infrared rays, the first and second terms of the equation (1) become 0, and the coefficient C is calculated from the voltage signal V, the absolute temperature TD of the reference junction, and the absolute temperature TE of the bowl. Is found. In the state B, the blindfold is removed, and the voltage signal V, the absolute temperature TR of the rotating body, and the absolute temperature T of the reference contact are obtained.
D, the coefficient b is obtained by substituting the coefficients a and c into the equation of Equation 1 using the absolute temperature TE of the bowl.

[0014]

According to the present invention, infrared rays are detected and output signals are output.
Of detecting the reference junction temperature of an infrared temperature sensor that generates a signal
Provide a step so that the reference junction temperature and the bowl temperature are almost equal
And the difference between the temperature of the rotating body and the reference junction temperature is not zero
From the temperature of the bowl using the first coefficient.
From the state where the difference between the temperature and the reference junction temperature is not zero, the second coefficient
The temperature of the rotating body can be accurately determined by a simple method.
Degree can you to measure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a thermocouple type infrared temperature sensor, an amplifier circuit, and a microcomputer showing an embodiment of a rotating body temperature measurement position of a centrifuge according to the present invention.

FIG. 2 is a configuration diagram of a centrifuge.

FIG. 3 is a graph showing a method for calculating coefficients a, b, and c of a temperature calculation formula.

FIG. 4 is a structural diagram of a thermocouple type infrared temperature sensor.

[Explanation of symbols]

1 is a thermocouple type infrared temperature sensor, 2 is a heat receiving part, 3 is a thermocouple, 4 is a reference contact, 5 is a reference contact temperature sensor, 6 is a supporting substrate, 7 is a rotating body, 8 is a cooling / heating bowl 9 Bowl temperature sensor, 10 is an amplification circuit, 11 is A / D
A converter, 12 is a CPU, 13 is a ROM, 14 is a D /
A converter.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-221823 (JP, A) JP-A-62-163937 (JP, A) JP-A-1-174062 (JP, U) (58) Survey Field (Int. Cl. ⁷ , DB name) B04B 15/02 G01J 5/00

Claims (1)

(57) [Claims] A rotating body rotated by a driving unit;
A rotating chamber capable of accommodating a rotating body, and a bow forming the rotating chamber
Red for measuring the temperature of the rotating body.
External temperature sensor and for measuring the temperature of the bowl
Detects infrared light in a centrifuge equipped with a temperature sensor
Reference contact of the infrared temperature sensor for generating an output signal
A temperature detecting means is provided, and the temperature of the reference
The temperature of the rotating body and the reference contact
From the state where the difference from the point temperature is not zero, the first coefficient is obtained,
Using a first coefficient, the temperature of the bowl and the reference contact temperature
Finding the second coefficient from the state where the difference from the degree is not zero
A non-contact temperature measuring system for a centrifugal separator , wherein the temperature of the rotating body is measured .