JPH0342525A - Measuring instrument for level and average temperature of tank - Google Patents

Abstract

PURPOSE:To shorten the time required for gathering of all data by receiving level data from a level measuring instrument by an average temperature measuring instrument to measure an average temperature corresponding to this level. CONSTITUTION:A level measuring instrument 2 has a function to communicate with a receiver 5 and an average temperature measuring instrument 3 by one unit 10b and the other unit 10a respectively. These devices are connected by an optical cable 4 and are operated. When receiving level data, the measuring instrument 3 selects an adapted thermometric element to measure the average temperature and transmits this data to the measuring instrument 2. The measuring instrument 2 stores received average temperature data in a memory together with level data. When a data request is issued from the receiver 5 to the measuring instrument 2, the measuring instrument 2 immediately returns level data and average temperature data stored in the memory to the receiver 5. Since the receiver 5 obtains level data and average temperature data immediately when issuing the data request, the data gathering time is shortened.

Description

[Detailed Description of the Invention] <Industrial Application Field> This device is mainly used for measuring the liquid level in large tanks such as petroleum @seedling tanks and tanker tanks.

Current status and problems〉 So-called two-way communication measuring devices, in which on-site measuring devices operate according to commands from a receiver and send data back to the receiver, have come into widespread use; The newest species measuring device is an optical communication type measuring device that uses optical fiber cables for bidirectional communication.

Optical communication systems have recently been put into practical use as devices for measuring the level and average temperature of liquid in tanks.

At present, as shown in Fig. 3, a level measuring device 2 and an average temperature measuring device 3 are installed separately on the upper part of the tank 1 and communicated with the receiver 5 through optical cables 4a and 4b, respectively.
As shown in the figure, the detector 7 of the average temperature sensor 6 is connected to the level measuring device 2 with a multicore electric cable 8, and a temperature measuring circuit is provided inside the level measuring device 2 to obtain temperature data. A method is used in which both data are transmitted from the level measuring device 2 to the receiver 5 via an electric wire 9.

The average temperature sensor 6 has an electrical configuration as shown in FIG.

That is, several resistance wire type temperature measuring elements 6a, 8 are included in the sensor.
b・・8n, each element has an overall resistance T1◆r2◆
The values of T3◆r4 are the same, but the distribution lengths of the resistance lines are different.

When measuring the average temperature of the armpit, among these elements,
All resistors rl+r7◆r3◆r4 are in the liquid,
The element whose distribution length is closest to the liquid level is selected, and the average temperature is determined from the total resistance value of this element. Therefore, level data is required for element selection.

In the method shown in the MS3 diagram, current level data is sent from the receiver 5 to the average temperature measuring device 3, and the average temperature measuring device can select a temperature measuring element that matches this level data and perform measurement. The receiver must transmit level data to the average temperature meter before obtaining temperature data.
Therefore, the more instruments connected to the receiver, the more time it takes to collect all the data.

In the method shown in FIG. 4, since a suitable temperature measuring element can be selected inside the level measuring device 2, the receiver 5 can receive the level and average temperature data from the level measuring device 2 at the same time. The time required to collect data is much shorter than in Figure 3.

However, a multicore electric cable is required between the temperature measuring element and the level measuring device, and the advantages of the optical cable communication method, such as lightning resistance and electromagnetic noise resistance, are significantly impaired.

OBJECTS OF THE INVENTION The present invention eliminates the use of electrical cables for signal processing and communication, significantly reducing the advantages of the optical cable system, and reducing the amount of time a receiver would spend transmitting level data to an average temperature measuring device. The time required to collect all data can be reduced by T1, and the length of the optical cable required for one communication can be made as short as possible, thereby reducing cable installation costs.

Means of the Invention The device of the present invention is applicable to a tank level and average temperature measurement device that uses a level measuring device, an average temperature measuring device, and a receiver, and communication between these devices is performed by an optical fiber cable. , the level measuring device is equipped with two optical communication input/output units, and has a function that allows communication with a receiver using one, and communication with an average temperature measuring device using the other,
The structure is such that the average temperature measuring device receives level data from the level measuring device, measures the average temperature corresponding to this level, and transmits the data to the level measuring device.

<Example> Embodiments of the present invention will be described below with reference to FIG. 1.2.

The device of the present invention is configured of a level measuring device 2, an average temperature measuring device 3, and a receiver 5 like the conventional device shown in FIG. 3, but as shown in FIG. 1, an optical cable is connected to the level measuring device. Communication input/output unit (called optical input/output unit) I
Two Oa and lOb are provided.

The optical input/output units 10a and 10b convert optical signals sent through optical cables into electrical signals.

Converts internally generated electrical signals into signals that can be transmitted over optical cables.

One of the two optical input/output units 10b of the level meter has the function of communicating with the receiver 5, and the other one 10a has the function of communicating with the average temperature measuring device 3, and the three types of devices are connected using the optical cable 4. Connected and working.

When there is no data request from the receiver 5, the level measuring device 3 repeats the level measurement at predetermined time intervals and stores the data in the memory, but immediately after performing the level measurement, the average thermometer 311 Send level data.

When the average temperature measuring device 3 receives the level data, it selects a suitable temperature measuring element, measures the average temperature, and transmits this data to the level measuring device.

The level meter side 42 stores the received average temperature data in a memory together with the level data.

When a data request is issued from the receiver 5 to the level measuring device 2, the level measuring device 2 immediately returns the level and average temperature data stored in the memory to the receiver.

In such an operation, the receiver can obtain level and average temperature data immediately upon making a data request, so that data collection time can be shortened.

Furthermore, since the average temperature measuring device receives level data from the level measuring device, there is no time delay in the level data, and the correct temperature measuring element can be selected.

In addition, Fig. 2 shows one receiver 5 and three level meters vA6.
This is an example of a communication time chart of a device composed of temperature measuring instruments 2 to 2 to 2-3 and average temperature measuring instruments 3-1 to 3-3. All you have to do is measure the level and communicate with the average temperature measuring device while receiving data from the It! The space between j can be used for right movement.

In addition, if you compare the fJS1 diagram and the conventional device shown in Figure 3, I
However, since the level measuring device and the average temperature measuring device are placed at a relatively short distance, the required amount of optical cables can be greatly reduced, and the cost can be reduced.

The operation time and effort described above is just an example, and even if the distance is 1,000 meters other than this procedure, by using the communication means of the present invention,
Needless to say, it is possible to shorten the time it takes for the receiver to collect all the data.

[Brief explanation of drawings]

Fig. 1 is a wiring system diagram showing an example of the device according to the present invention, Fig. 2 is a diagram showing a time chart of measurement sowing, wS3 Fig. 4 is a diagram showing a conventional example, Fig. 5 is an average temperature It is a figure showing a sensor. In the diagram 1...Tank 2...Level meter Δ-meter 3...Average temperature measuring device 4...Optical cable 5...Receiver 0a 0b Input/Output Kaninirat

Claims (1)

[Claims] A tank level and average temperature measuring device that consists of a level measuring device, an average temperature measuring device, and a receiver, and communication between these devices is performed using an optical fiber cable.
The level measuring instrument is equipped with two optical communication input/output units,
Equipped with a function that allows communication with the receiver using one side and communication with the average temperature measuring device using the other side, so that the average temperature measuring device receives level data from the level measuring device and the average temperature corresponding to this level. A tank level and average temperature measuring device characterized by having a function of measuring temperature and transmitting the data to a level measuring device.