JPH0719007Y2 - Clamp type ammeter for piping - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a clamp type ammeter for pipes, particularly for measuring the current flowing in buried pipes.

[Conventional technology]

Buried pipes are used to transport dangerous materials such as scraps and oil. Although steel pipes coated with coating are generally used for these buried pipes, current may flow in the pipes due to the influence of the soil difference in the buried condition and the leakage current of a train or the like. When this electric current flows out into the soil from a defective portion of the coating or a metal exposed portion such as a valve, corrosion corresponding to the electric current occurs.

In the transportation of the above-mentioned dangerous substances, if a through hole is generated due to corrosion, it would be a catastrophic event. Therefore, the measurement of the in-pipe current is very important for maintenance management. A clamp-type ammeter is usually used to measure the in-tube current.

Clamp-type ammeters are measuring instruments mainly for measuring the current flowing through electric wires, and there are commercial products, but since the clamps generally have only a small diameter, various types with a large diameter (for example, several cm or more in diameter) For the current measurement of the pipe, a clamp part was prepared separately according to the pipe diameter.

[Problems to be solved]

As described above, in order to measure the electric current in the pipe, it is necessary to prepare a clamp portion corresponding to various pipe diameters, which has been a very expensive measuring instrument in the past.

In addition, since the conventional clamp type ammeter has an all-clamping clamp part made of an iron core, the entire circumference of the measured pipe to be clamped is exposed and other structures do not interfere with the measurement. There was a problem that it could only be used.

The present invention solves the above-mentioned problems, can be applied to pipes of various diameters, can be manufactured at relatively low cost, and has a clamp type ammeter for pipes with a clamp part that does not restrict the measurement position too much. It is intended to be provided.

[Means for solving problems]

In order to achieve the above-mentioned object, in the present invention, a clamp part equipped with a semi-annular arm formed so as to sandwich the vicinity of the diameter position of the pipe to be measured has a semi-circular shape for pipes to be measured having different pipe diameters. It was possible to attach a semi-annular adapter that adapts the arm.

Hall elements are housed at the symmetrical positions of the tips of the semi-annular arms, and the Hall element generates a magnetic field based on the pipe current when the vicinity of the diameter of the pipe to be measured is clamped. The measured magnetic field value was sent to the measuring instrument body, converted into a current value corresponding to the magnetic field measured value input in the measuring instrument body, and then displayed.

Further, a polarity reversing switch is provided in the measuring device main body so as to save the trouble of reversing the clamp part and performing the magnetic field measurement.

[Action]

According to the clamp type ammeter for piping of the present invention, the current flowing through the piping can be measured by sandwiching the piping to be measured with the clamp part so that the two Hall elements face each other in the vicinity of the diameter position of the piping.

Also, if it has a clamp part equipped with a semi-annular arm that can be applied to large-diameter pipes, in the case of pipes with smaller diameters, a semi-annular adapter that matches each pipe diameter should be attached to the clamp part. It is possible to measure the electric current only by mounting it on the board so that the Hall element is accurately positioned.

Furthermore, the clamp part may be reversed to eliminate errors other than the magnetic field generated by the current in the pipe to be measured, but the polarity of the Hall element output voltage can be reversed by providing a polarity reversing switch. Easy to do.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to embodiments.

FIG. 1 shows a structure of a clamp portion according to an embodiment of the present invention. FIG. 1 (a) is a front view and FIG. 1 (b) is a side view.

In the figure, the semi-annular arms 2 ₁ and 2 _{2 house} the Hall elements 3 ₁ and 3 ₂ which are magnetic sensors, respectively, at the tips thereof, and two stoppers 4 _{1 on} the A surface of the clamp unit 1
4 ₂ and stopper plate 5 is provided in order to attach to position the adapter 9 of the semi-annular shape, the clamp portion 1
The Hall element 3 ₁ is installed inside the grip 6 attached to the lower side of
A connecting wire 7 for sending the output signals of 3 and 3 ₂ to the measuring instrument main body (not shown) is inserted, and the output signal circuits of the Hall elements 3 ₁ and 3 ₂ are connected in series.

The center position as in a symmetric position of the 8 Hall element 3 ₁ and 3 ₂ are opposed, clamping the adapter 9 of the semi-annular shape corresponding to the different measured pipe of pipe diameter to be measured pipe (not shown) Attach to part 1.

Next, the handling method of the clamp type ammeter for piping provided with the clamp part 1 of this invention is demonstrated.

The Hall elements 3 ₁ and 3 ₂ generate an output in proportion to the magnitude of the magnetic field generated by the current in the pipe, but they amplify a very weak magnetic field, so that the zero point is affected by the earth's magnetism and nearby objects. It depends on the situation.

Therefore, the current in the pipe is turned off and zero adjustment is performed,
After that, the amount of change may be measured by turning it on. However, it is impossible to turn off the current of the existing pipe from the practical point of view.
After that, turn the clamp unit 1 over and measure with the B side up
The magnetic field measurement value based on each measurement result is input to the measuring instrument main body, converted into a current value corresponding to the magnetic field measurement value, and then displayed.

Even if the polarity reversing switch is provided in the measuring device main body instead of reversing the clamp portion 1, the same measurement can be performed.

2 (a) and 2 (b) show semi-annular adapters 9 having different diameters.

Note that FIG. 2 (c) shows the semi-annular adapter 9 mounted on the clamp part 1.

In the figure, a mounting hole provided in the semi-annular adapter 9
10 ₁ and 10 ₂ and 11 are positioned and fixed stopper 4 ₁ is provided on the clamping unit 1 and the 4 ₂ and catch 5 (see FIG. 1) to the clamp unit 1.

If the clamp part 1 is manufactured for a large diameter and a plurality of semi-annular shaped adapters 9 are prepared in advance to match pipes of various smaller diameters, various types of pipes of different diameters can be prepared. The current in the tube can be measured.

The clamp part 1 and the semi-annular adapter 9 are provided for positioning and fixing the Hall elements 3 ₁ and 3 _{2 of the} clamp part 1 on the diameter line of various measured pipes. It can be easily made using a magnetic material (for example, an aluminum plate).

FIG. 3 shows an example of test data conducted using the clamp unit 1 of the present invention. The diameter of the pipe used for the test is 6 inches, the horizontal axis of the figure is the value of the current actually applied to the pipe, and the vertical axis is the reading of the meter of this measuring instrument.

The results of measurement repeated three times show good linearity as shown in the figure.

〔effect〕

As described above, since the clamp type ammeter for piping of the present invention uses the clamp part having the semi-annular arm, if the clamp part can be inserted so that the diameter part of the pipe to be measured is clamped, The internal current can be measured, and the measurement place is less restricted by the structure.

Also, the clamp part and the semi-annular adapter with semi-annular arms can be easily made using non-magnetic material, and the semi-annular adapter can be used to measure the current of pipes of various diameters. Since it is possible, the cost of the measuring instrument can be reduced significantly.

[Brief description of drawings]

FIG. 1 shows the structure of the clamp portion of the present invention. FIG. 1 (a) is a front view and FIG. 1 (b) is a side view. FIG. 2 is a front view of a semicircular adapter for clamping, where FIGS. 2 (a) and 2 (b) have different calibers, and FIG. 2 (c) shows a state where the adapter is attached to the clamp portion. FIG. 3 is a graph showing test data of a clamp type ammeter for piping provided with the clamp part of the present invention. 1 ...... clamping unit 2 _1, 2 ₂ ...... semiring-shaped arm 3 _1, 3 ₂ ...... Hall element 8 ...... the center position 9 ...... semiring profile of the measurement pipe adapter

Claims (1)

[Scope of utility model registration request] 1. A semi-annular arm formed so as to sandwich the vicinity of the diametrical position of the pipe to be measured, the Hall elements being housed at symmetrical positions of the tip of the semi-annular arm, and the pipe diameters being different. A clamp part made of a non-magnetic material that can be fitted with a semi-annular adapter that adapts the semi-annular arm to the pipe to be measured, and a semi-annular shape with a diameter corresponding to the pipe diameter of the pipe to be measured. ,
Input an output signal that is a series connection of the output of each Hall element provided in the clamp part and the adapter made of a non-magnetic material that can be positioned and fixed in the clamp part, and set it to the current value flowing in the measured pipe. A clamp type ammeter for piping, comprising a polarity reversing switch for inverting the polarity of the output signal of the Hall element, the polarity reversing switch being configured by a measuring instrument body for converting and displaying.