Remote differential pressure transmitter and zero adjustment method

Abstract

This application is applicable to the technical field of industrial automatic control equipment, and provides a remote differential pressure transmitter and a zero adjustment method. The remote differential pressure transmitter further includes a diaphragm box and an adjustment device. A first storage cavity communicating with the low-pressure side storage cavity and a second storage cavity communicating with the first storage cavity are arranged in the diaphragm box; a first adjustment component of the adjustment device is used to adjust the volumes of the first storage cavity and the second storage cavity, and a second adjustment component is used to control the communication and closing between the first storage cavity and the second storage cavity. For the remote differential pressure transmitter provided in this application, by installing a diaphragm box outside the remote differential pressure transmitter body and adjusting the volumes of the first storage cavity and the second storage cavity through the first adjustment component, the error between the high-pressure side storage cavity and the low-pressure side storage cavity is adjusted, and the problem of low accuracy caused by the volume difference and temperature difference on both sides of the remote differential pressure transmitter is eliminated, improving the measurement accuracy of the product.

Claims

1. A method for zeroing a remote differential pressure transmitter, the remote differential pressure transmitter comprising a transmitter body and a control display device, the transmitter body being provided with a high-pressure side storage cavity and a low-pressure side storage cavity, the control display device being used to obtain the pressure values of the high-pressure side storage cavity and the low-pressure side storage cavity; characterized in that: The remote differential pressure transmitter also includes: A diaphragm box, wherein a first storage cavity communicating with the low-pressure side storage cavity and a second storage cavity communicating with the first storage cavity are disposed in the diaphragm box; A regulating device, the regulating device comprising a first regulating component and a second regulating component respectively arranged on the membrane box, the first regulating component is used to adjust the volume of the first storage cavity and the volume of the second storage cavity, and the second regulating component is used to control the connection and closing between the first storage cavity and the second storage cavity; The zeroing method comprises the steps of: S1, adjusting the second adjustment component of the remote differential pressure transmitter to connect the first storage cavity with the second storage cavity, thereby achieving communication between the low-pressure side storage cavity and the second storage cavity; S2, obtaining the current temperature value and the display value of the control display device; S3, under the obtained current temperature value, according to the obtained display value of the control display device, control the first adjustment component to adjust the volume of the first storage cavity and the volume of the second storage cavity; when the display value of the control display device reaches a preset value, stop adjusting the first adjustment component, and lock and fix the first adjustment component and the second adjustment component.

2. The zeroing method of the remote differential pressure transmitter according to claim 1, characterized in that: The first adjustment assembly includes adjustment shafts respectively disposed in the first storage cavity and the second storage cavity; A top ring is sleeved on the adjusting shaft and abuts against ends of the first storage cavity and the second storage cavity.

3. The zeroing method of the remote differential pressure transmitter according to claim 2, characterized in that: The first adjustment assembly further includes a sealing ring, which is disposed between the top ring and ends of the first storage cavity and the second storage cavity.

4. The zeroing method of the remote differential pressure transmitter according to claim 2, characterized in that: The first adjustment component also includes a fastening ring, which is sleeved on the adjustment shaft and is provided with a first connecting portion. The top ring is provided with a second connecting portion. The first connecting portion is connected to the second connecting portion to lock the rotation of the adjustment shaft.

5. The zeroing method of the remote differential pressure transmitter according to claim 2, characterized in that: A rotating head is provided on one end of the adjusting shaft close to the outer side of the membrane box, and the rotating head is a square head; or a straight opening is provided on the rotating head; or The rotating head is provided with a cross-shaped opening; or The rotating head is provided with a square hole or a polygonal hole.

6. The zeroing method of the remote differential pressure transmitter according to claim 1, characterized in that: The second adjustment component comprises: An adjustment seat, wherein a mounting cavity is provided in the adjustment seat and the adjustment seat is arranged in the membrane box; A regulating valve core is rotatably disposed in the installation cavity, and one end of the regulating valve core abuts against the connection between the first storage cavity and the second storage cavity, and the other end of the regulating valve core is close to the outside of the membrane box, and a rotating head is disposed at the other end of the regulating valve core.

7. The zeroing method of the remote differential pressure transmitter according to claim 6, characterized in that: The membrane box is provided with a cavity communicating with the second storage cavity, and the cavity is provided at the connection between the first storage cavity and the second storage cavity; The adjustment seat comprises: A sealing ring, the sealing ring being attached to the opening end of the cavity; A fixing ring is provided with a pressure ring connected to the sealing ring, and a rotating opening is provided on one end of the fixing ring close to the outer side of the membrane box.

8. The zeroing method of the remote differential pressure transmitter according to claim 1, characterized in that: In step S3, the steps are also included: S301. When the display value of the control display device obtained is within the first preset range value, control the first adjustment component to make the oil fluid in the second storage cavity flow into the first storage cavity. When the display value of the control display device is the preset value, stop adjusting the first adjustment component and lock and fix the first adjustment component and the second adjustment component. S302. When the display value of the control display device obtained is within the second preset range value, control the first adjustment component to make the oil fluid in the first storage cavity flow into the second storage cavity. When the display value of the control display device is the preset value, stop adjusting the first adjustment component and lock and fix the first adjustment component and the second adjustment component.

9. The zeroing method of the remote differential pressure transmitter according to claim 1, characterized in that: The zero adjustment method further includes the steps: S4, respectively, when the current temperature value is the first temperature value t1, the second temperature value t2, the third temperature value t3, ... the nth temperature value t n Repeat steps S1, S2 and S3 to record the preset values A1, A2, A3... A n , according to the formula: |A1 - A2| = k + X1×(t2 - t1); |A3 - A2| = k + X2×(t3 - t1); …… | A n - A n-1 | = k + X n ×(t n - t n-1 ); where k is the range accuracy of the remote differential pressure transmitter, t n is greater than t n-1 , and X is a constant; S5, calculate X1, X2, X3, ... X respectively. n , use the finite element function to fit a horizontal straight line and get the final constant X.

Images