JPH0552666A - Plane temperature measurement sensor - Google Patents

Abstract

PURPOSE:To reduce the turbulence of flow and thermal field at temperature measuring time so as to measure an absolute temperature simply and accurately by arranging temperature measurement resistors in a plane grid form and wiring them. CONSTITUTION:A simple drive circuit having no switch is formed by arranging temperature measurement resistors R (thermistors or platinum resistance wires are used) in a plane grid form and wiring them. When a voltage E is loaded, potential differences of both ends in a column R21, R31 and a row R12, R13 become 0, so that no current flowing through extra paths flows through an ammeter A. This way, it is possible to measure resistance at any place by applying a positive or a negative voltage to the column and the row, and reversing the voltage of the column and the row to be measured so as to measure a current value flowing there. As such a measuring function is applicable to an enlarged resistors network, the function can be expanded up to such many elements as 50 columns and rows, so that it is possible to measure the temperature distribution of a large plane accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat temperature measuring sensor capable of accurately measuring the temperature distribution of a flat heated object such as an electronic substrate.

[0002]

2. Description of the Related Art Conventionally, as means for measuring the temperature distribution of an object to be heated, a method of installing a sensor such as a thermocouple at each measuring point, or a non-contact type temperature measuring sensor such as a radiation thermometer is scanned. The method etc. have been mainly used. Of these, the former method has the advantage of being able to measure the temperature distribution most directly, but if many detailed measurements are taken, the leads will flow, disturbing the heat field and spending a lot of time on setting. Therefore, it is not suitable for accurate temperature measurement. Further, the latter method has an advantage that a fine temperature distribution can be measured within a short time, but has a drawback that the emissivity and the like change if a different measurement surface exists. For this reason, in order to make the emissivity uniform, it is necessary to take measures such as coloring the whole in black or measuring while applying emissivity to the measurement position. Further, in the measurement inside the housing, it is necessary to install a portion such as a window where light can be seen in a part of the housing, and there is a problem that temperature cannot be measured at a portion that cannot be directly observed with the naked eye.

In addition, a method of arranging the sensors in a line and mechanically scanning them or estimating a two-dimensional temperature distribution from a one-dimensional temperature distribution is also known. This method is effective for obtaining a one-dimensional temperature distribution, but when measuring the temperature distribution on a plane, accurate temperature measurement operation cannot be performed due to flow and thermal influences. Moreover, there is a drawback that the measurement takes time.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems in the conventional temperature measuring technique described above, and there is little disturbance in the flow or thermal field at the time of temperature measurement, and the absolute temperature is always absolute. It is an object of the present invention to provide a flat temperature measuring sensor that can measure temperature easily and accurately.

[0005]

A flat temperature measuring sensor according to the present invention for achieving the above object is characterized in that the resistance temperature detectors are arranged and connected in a plane grid pattern.

FIG. 1 is a circuit diagram schematically illustrating a flat temperature measuring sensor according to the present invention, in which the resistance temperature detectors R arranged in a plane grid are connected to the lead wires which cross the columns in the vertical and horizontal directions. Wired to form a sensor. As the resistance temperature detector R, a thermistor or a platinum resistance wire is used. Usually, in order to measure individual resistance elements in this type of resistance network circuit, it is necessary to provide a switch element such as a diode between the resistance temperature detector and the lead, or to specify the measurement position with a probe. However, the mechanism of the present invention does not require the installation of these switching elements and probes.

To measure the resistance network of the flat temperature measuring sensor of the present invention, a method of applying a constant voltage and calculating from the value of the flowing current is adopted. At this time, for example, when measuring the grid points of row 1 and row 1, + is applied to row 1 and other rows 2 are measured.
By applying − in the following, applying − in the other row and applying + in the other rows and below, the resistance element at each lattice point can be independently measured.

[0008]

The flat temperature measuring sensor according to the present invention can be configured as a simple drive circuit having no switches by arranging and connecting the temperature measuring resistors in a plane grid pattern. The principle will be described based on the circuit diagram of FIG. 2. When the voltage E is loaded, the potential difference between both ends in the columns R ₂₁ , R ₃₁ and the rows R ₁₂ , R ₁₃ becomes 0, and the current flowing through the extra path is measured by the ammeter A.
Will not flow into. In this way, positive and negative voltages are applied to the rows and columns, the voltages of the rows and columns to be measured are reversed, and the value of the current flowing therethrough is measured, so that the resistance can be measured at any place. Since the measurement function does not change even if the number of resistance networks is increased, it can be extended to large elements such as 50 rows and 50 columns, and the temperature distribution on a wide plane can be accurately measured.

[0009]

[Example] A flat temperature measuring sensor was manufactured by connecting a 5 kΩ thermistor at each crossing position of leads arranged in a grid pattern of 7 rows and 7 columns and joining them to a glass / epoxy substrate, and as shown in the circuit pattern of FIG. It was connected to the measurement controller via the scanner, DC stabilized power supply, digital multimeter for thermocouple measurement and digital multimeter for resistance measurement by the control and communication line (GP-IB). In addition, a thermocouple (type T) was attached to the scanner to check the temperature consistency. Room temperature (20 ℃) was measured using this device, and it was 5 kΩ ± 100 for all measurement points.
Ω was shown, indicating good accuracy.

Next, as shown in FIG. 4, the planar heating element 2 is partly overlapped with the planar heating element 2 to measure the temperature distribution. Contrasted. The result is shown in FIG. The numerical values in FIG. 5 are measured temperatures (° C.), and the numerical values in parentheses are measured values by thermocouples. From the temperature measurement result of FIG. 5, it was confirmed that the flat temperature measurement sensor of the present invention and the measurement temperature of the thermocouple matched with each other with an accuracy of about ± 1 ° C., and were highly accurate.

[0011]

As described above, the flat temperature measuring sensor of the present invention can always measure the temperature distribution in a wide area with high accuracy by the simple grid connection of the driving circuit. Therefore, it is extremely useful for various industrial temperature measuring operations.
Furthermore, by not using a switching element or the like, it can be applied to a curved surface.

[Brief description of drawings]

FIG. 1 is a circuit diagram schematically showing a flat temperature measuring sensor of the present invention.

FIG. 2 is a circuit diagram for explaining the principle of the present invention.

FIG. 3 is a circuit pattern used in an example.

FIG. 4 is an explanatory diagram showing a temperature measurement state in the example.

FIG. 5 is a distribution diagram showing temperature measurement values at respective measurement points in the example.

[Explanation of symbols]

 1 Flat surface temperature sensor 2 Sheet heating element 3 Measurement point

Claims (1)

[Claims] 1. A flat temperature measuring sensor, characterized in that the temperature measuring resistors are arranged and connected in a plane lattice shape.