Some standard content:
Verification Regulation of Target Flow Transmitter
JJG 461 -1986
Verification Regulation of Target Flow Transmitter
LIG 461--1986
This verification procedure was approved by the State Bureau of Metrology on November 1986, and will be implemented from October 1, 1987. Importing unit: Henan Bureau of Metrology
Drafting unit: Henan Metrology and Testing Institute The drafting unit of this regulation is responsible for the interpretation of the text. The main drafters of this regulation:
Xiao Hanli (Henan Metrology and Testing Institute) 28
Technical requirements
(1) General requirements
(2) Transmitter plate and measuring tube
3. Verification conditions
, Verification items and verification methods
(1) Daily weight method for electric transmitter (2) Monthly balance method for pneumatic transmitter
(3) Unit measurement marking for transmitter (3) Replacement of suction table for verification...
Verification result processing and verification period
Record! Appendix 2 Calibration record of target flow transmitter Appendix 3 Calibration of target flow coefficient and its error
Calculation of flow rate accuracy
Method for determining the physical parameters of the measured fluid
Appendix 5
Appendix 7
Appendix 8
Practical calculation formula for flow rate and sono number
Example of transmitter selection
Status
: 1242
Calibration procedure for target flow transmitter
This calibration procedure The process is timely and the gas is analyzed. The standard for the final use is: 1. The target type flow transmitter is composed of a measuring device and a sensor. The flow meter includes a measuring coil: a force converter is divided into two structural types: an electric target type flow transmitter with a force (electric) converter: a pneumatic target type flow transmitter with a force (pressure) converter, 2. The target flow transmitter (hereinafter referred to as a "target flow transmitter") is equipped with the instrument and becomes an instant flow meter, which can measure the flow of the body and gas. |Transmitter working principle
In the figure of the constant induction surface, there is a circle called "" at the center of the straight pipe section and the direction of the flow. When the flow passes through the target, it is affected by the torque, and the size is proportional to the kinetic energy of the structure and the circular area. When the flow rate of the pipe exceeds the limit of the transmitter, the required flow rate and the force on the target have a certain relationship. The following basic formula can be used for reverse calculation, and the technical formula for the calculation of the field
4m=1.253a
is: m mass flow, kg/s
Volume density,;
Flow coefficient (pure number);
Flow expansion coefficient (number), for incompressible fluids =, for compressible fluids; a standard inner diameter, 1m
—diameter, m
pFluid density, kgm:
Climbing to,.
4.1 Flow coefficient c
Length is the change in the energy of the liquid flowing through the annular gap. Under the working conditions of continuous flow paper 4 (integrated), under the force on the upper surface, a coefficient is obtained by the following formula. 1.253
1.253 D-4E
is a pure number, and the actual calibration results are: its calibration method is shown in the scientific record 3, the actual measurement. With the increase of the required number, it increases. When Re is within the range of a number Re, the value of α remains unchanged. Re, the limit number, for this type of transmitter, the most required number of inches, when R>e, its. The equal. 4.2 The skin coefficient 7
is the measurement of the compressed fluid flowing through the ring source [with a source of pressure. With a (or) as the work, that is, the upper household, the following formula is used to obtain the coefficient. (5)
is the flow coefficient of the transmitter determined by the direct calibration method in the teaching section 1.1 under the same conditions as the compressed fluid number
5 fluid conditions
5.1 must be a flow companion.
5.2 The fluid should be in accordance with the first principle and thermodynamics, and should be in accordance with the requirements of the principles and conditions of the early secretion. 5.3 The flow must fill the transmitter and the measuring section of the pipeline. 5.4 The fluid must not undergo phase change when flowing through the transmitter. If it is determined that there is enough phase change, when calculating the flow total, it can be assumed that the flow rate is equal to the flow rate of the tank. For liquids, it can be assumed that the flow rate is equal to the flow rate of the tank. 5.5 The flow rate should be sufficient to meet the requirements of the machine, and it should change slowly with the light of the day. It is not applicable to the transmitter of electric pulse flow and critical temperature.
6 Installation requirements
.1 The pipeline where the transmitter is installed should be bypassed. As shown in Figure 1. There should be vertical pipe sections and square sections before and after the measuring device. The diameter is equal to the diameter of the measuring pipe. The length of the upper and lower sections (also called the front straight pipe section) is not less than 10), and the length of the straight pipe section (also called the rear straight section) is not less than 5. The inner hole of the sound pipe is circular and the diameter is checked by the daily measurement method. When the straight pipe section is connected to the measuring device, the misalignment should not exceed 0.3% of the sound diameter T> measured in Article 15.1. The gate valve is used, the upper gate is fully opened, the lower gate is fully closed, and there is a small seepage. The downstream valve 5 is used to adjust the flow. The target and measuring tube are required to be installed coaxially, and the eccentricity should not be more than 0.3% of the average value of the measuring tube point weight measured according to Article 13.1; the upstream end face of the target should be perpendicular to the line of sight, and the deviation should not exceed 1%. The maximum pressure difference of the fluid flowing through the target can be taken as the static pressure difference at the static pressure point 4D (nominal diameter of the measurement) upstream of the transmitter. It can be concluded that when the transmitter is used to measure the flow rate, the linear velocity R of the pipeline should be 2.0 μm. Technical requirements: (-) General requirements: 1. The transmitter should be well assembled and have special accessories and 2. 3. 4. 5. 6. 7. 8. 9. 10. The newly manufactured transmitter should be accompanied by an instruction manual, and the last calibration certificate should be included in the usage and maintenance information. The instruction manual shall specify the technical specifications of the transmitter, as well as the coefficients. , limit harmonic number Re, and technical coefficient Li.
Newly manufactured transmitters must comply with the provisions of this regulation, provide the value of the actual coefficient of force, but for the determination of force, see Appendix 10.1
Newly manufactured transmitters must specify the actual upper limit of the force and the maximum measurement range of the flow rate. When using and using the transmitter, confirm the actual upper limit of the force and the range of flow measurement with the actual situation. 11 The accuracy of the transmitter meets the following requirements [see the table below] The transmitter has a storage plate, and the nameplate shall indicate the factory name or! The name and type of the product must be marked with the explosion-proof mark, equipment number, equipment number, technical indicator, year of manufacture, and explosion-proof grade of the product must be clearly stated and have a coal-proof certificate. (ii) Target installation and measurement method: 1. The target plate is also called "target", which is a thin plate with a round end and a sharp edge as specified in the target regulations. The target is rotationally symmetrical relative to the measuring tube, and its rotation angle is shown in Figure 2. 14 target plate
14.1 Put the upstream sliding surface of the plate into the measuring tube, and the material ratio between the straight line read backward from any upper point and the plane perpendicular to the lower center line should be less than 1%. The entire A surface can be seen to be transmitted, and its accuracy is 14.1. The downstream end surface B of the target plate is parallel to the A surface, and the thickness measured at more than two points on the target plate is less than 10.KII (D is the nominal point diameter of the entire tube).
14.3 The slats and downstream sidewalls shall be free of burrs, scratches and visible damage.
14.4 The upstream edge is sharp. If the edge is sharp, the radius of return shall not exceed 0.004d (for light). The upstream edge (and downstream edge) shall be free of burrs, scratches and visible damage. 14.5 The target diameter shall be the arithmetic mean of not less than 4 individual measurements. The angles between these 4 individual measurements shall be equal, and the difference between any individual measurement and the average value shall not exceed ± 0.1%. Note: For air conveyors that meet the requirements of Article 13.1, it is not necessary to select the appropriate one in the instructions for use.
15.1. The diameter value to be measured should be the arithmetic half-mean of the inner diameter of the measuring tube at the upstream end of the target plate. This should be the arithmetic average of at least 4 diameter measurements. The single point measurement value should be compared with the average value, and the difference should not exceed ±0.3%. The actual value of each value is distributed in 3 sections 1. Two of the sections are divided at the upstream end and the upstream end of the measuring tube.
15.2 A straight line should be set on the upstream end of the target plate to the measuring tube downstream end for comparison, and the difference should not exceed ±3%.
15.3 The inner wall of the tube is smooth, without pits and sediments. 15.4 The value of L> specified in this regulation shall satisfy the following formula [5mm>m; 200m
diameter (=/) shall satisfy the following formula
three age conditions
bad conditions
ambient air temperature is 5-35t
17.2 The filterability of the ambient air is 10%-85%, 17.3 The ambient vibration is within the range of 3 perpendicular axes, and the drop amplitude is not greater than 0.07 mm, the rate range is 10.-·60Hx
17.4 The external magnetic field is greater than 4H)A/m [the medicine is 5 Oersted] 18 Main calibration equipment [see Table 1]
19 The standard device (hereinafter referred to as "device") shall meet the following requirements, 19,1" can be used as one of the following devices for calibration: soft method device:
h capacity visual device:
comparison method device.
The device must be calibrated regularly according to the relevant construction regulations. If there is no calibration, the accuracy of the device will not deteriorate by more than half of the device accuracy. We will try our best to use the actual working fluid as the working medium, otherwise, use the reverse medium instead. For the transmitter measuring incompressible fluid, water is used as the working medium; for the gas transmitter, air is used as the working medium: when the transmitter uses a high-density fluid with a small Reynolds effect and it is difficult to use water as the second medium, you can choose a piece of fluid with a viscosity and density close to the actual working fluid, and the difference between them is not too large, as shown in the table! Main calibration equipment list
Equipment
Iron tester
On-line current control
One input power
Allowed to stop
Single Bailey wind measurement
Standard is the table
I pressure gas source
R small measurement
5 force tester
Special or integrated
Effective human feed
For parts to eliminate the standard
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Pneumatic enterprise sends the air source used to show the lower dryness, Fan also, and the point is startled to measure the effective less impurities: the output of the pressure reducing valve is guaranteed to be in (0.E37±(.005)Ma［(1.40-0.05)kut/cn1IV. Verification items and verification methods
（） 21.1 The transmitter is in compliance with the requirements of Articles 9 to 2 of the enterprise. 21.2 Target plate inspection 21.2.1 Remove the transmitter for measurement and clean the period and measurement tube. Then use a special light (or a table) to tighten the force converter (disassembled target) so that the electrical plane is horizontal. 21.2.2 Check the semi-axial formation of the upstream surface of the target and the alignment of the upstream and downstream surfaces. Put the plate under the effect of 1. The inspection results are in accordance with the requirements of 14.1 and 12. 2, 2, 3. The target is inspected monthly. The results are in accordance with the requirements of 14.1 and 14.3. 21.2.4 According to the requirements of 14.3 and 14.4, the sharpness of the upstream end of the target and the angle of the reverse edge are calibrated.
21.2.4.1 Test late Check the sharpness of the edge of the upstream end, the target is inclined at 45, the mouth or the source of the agent is the same as the edge, and the eye is used to explore. There is no light reflection. 21.2.4.2 Regarding the requirements of the roughness research plan, it should be enlarged under 4 consultation. 21.2.4.3 Whether to produce 21.2.4.! The inspection results and the results of the inspection can be used; the die casting method or the aluminum first rate main compensation actual measurement 1. The middle diameter of the surface of the tour Swiss is reached || tt || 21.2.5 According to the requirements of Section 14.5, the size of the parts is small (Figure 2 in the year, on, and worn! The accuracy of the measuring instrument shall not be worse than one-fifth of the deviation of each part. The value of the transmitter after treatment shall be compared with the result of the last calibration or before treatment. If the deviation exceeds the specified value, the current coefficient of the transmitter shall be recalibrated according to Appendix 3.
Application: For large and medium-sized devices that meet the requirements of Articles 1+ and 14, the current transmitter shall be used in accordance with the technical specifications of 151.3 of the United States.
21.3.1: The vertical length of the measuring tube shall be measured according to the requirements of Articles 15.1 and 15.2: The accuracy of the measuring instrument shall not be less than 0.
21.3 .2 According to the requirements of Article 15.3, check the inner surface of the measuring mother back, 22 small value determination
23.1 Connect a 0.2 level current meter to the transmitter signal output. Some transmitters must be equipped with a negative resistor (refer to the transmitter manual). If there is no transmitter, connect a 0.10tL4 ammeter. If it is a type, connect a 0.20r14 current meter.
22.2 Verify the range adjustment,
22.2.1 Replace the fixed needle of the target with a hanging order with a small hole at the end, and install the board. The small hole in the ticket is used to hold the number of selected codes, so that the center of gravity of the code is always located in the center of the target. On the central axis, the gravity is perpendicular to the consumption plane. : The horizontal safety rate of the three-belt transformer is 3, and the empty line attached to the power return station should coincide with the axis of the distribution source. The resistance of the two wheels shall not be greater than UUSN (about .kF). 21.2.2 Connect the power (AC 220V, 50F), preheat 30n
and adjust the frequency converter: : Promote the ammeter pointer 21.2.3
to the lower limit value. The lower limit value of the mountain type converter is central, and the lower limit value of the Sichuan type converter is 4nA,
2.2.4 Force on the plate The actual limit code selection, through the adjustment program, make the meter indication lower than the upper limit
22,2.5 will be all the code down, at this time the ammeter pointer should be restored to the original lower limit position, otherwise, still according to 2.2.3 and 22.2.2 items for spectrum adjustment, the point drift should be measured,
for type II transformer, reduce more than 0.1mA,
for type Sichuan, no more than 1.2mA
small busy calibration.
2.3.1 According to the actual resistance value of the transmitter, the upper limit M is divided into 5 calibration points F, and the output signal nominal value corresponding to F is calculated. Refer to the following table:
Single diagnosis
Fixed point force position
Output signal position
Output signal position
22.3.2 Add the amplitude of the corresponding force value of each test point to the code disk in turn, and read the actual sequence of the output signal current. , the forward and reverse strokes are checked once each
22.3 The accuracy calculation formula of the target force value is as follows: For the basic variable
For the type transmitter
The accuracy of the target force value
The value is not bad 0.5%,
×100%
8y =± Byx a
22.3.4 Calculate the return distance AF of the target force, and the calculation formula is as follows: For the type II transmitter
For the pre-transmitter
1=×100%
I',- ×100%
《The actual value of the signal selection is obtained in the positive area of the nth control point: The return distance error of the force value
4. = (Ap.)nr
value is not greater than 0.5%
(Ap.)
22.3.5 For those who meet the requirements of 21.1 to 22.3.4. The transmitter shall calculate the accuracy of its flow rate measurement according to Appendix 4. The value of 3 shall not exceed 4%.
23 Static pressure and tightness test.
23.1 Replace the original target plate and assemble the transmitter according to the requirements of 6.2. Seal one end of the measuring tube with a square plate and connect the other end to the pressure tester as shown in Figure 4. 23.2
Release the screw, fill the measuring tube of the pressure tester with liquid (water or transformer extinguisher), and after the gas is non-condensing, release the condensation screw.
Figure 1 Flow disc variable reverse circuit static water and rate test 23.3 Static pressure error test: Under the condition of zero, make the output of the transmitter The estimated current ratio is maintained at the agreed value to allow any output current value to fall below the upper and lower limits, and then the type safety device is connected to quickly increase the positive force from the same value to the allowable working force (i.e. the maximum static pressure) value, and the signal current is filtered out during the process of decreasing the current. It should be within the allowable range:
type transmitter, the value does not exceed =0.3r4;
for type transmitter, I should =(.5A,
23.4 Tightness test: pressurize to 1.25 times of the rated working pressure: close the control valve, read the pressure indication after adjustment, and continue for 5mn. If the pressure drops by more than 1% of the rated working pressure, it is tight. 23.5 After the optical calibration, remove the board and the pressure pipe, and readjust the degree. 24 Insulation resistance and insulation strength test
24.1 Insulation resistance test. Use an insulation resistance tester to measure the insulation resistance values of the output terminal and the shell, the output terminal and the external end of the power converter. The output resistance value should meet the following requirements: a. The resistance between the output terminal and the external end should not be less than 20M; the resistance between the power cord and the shell should not be less than 50M; the resistance between the power cord and the output terminal The value is not less than 0.424.2 Insulation strength test: Connect the converter output, power supply terminal and shell, power supply terminal and output terminal to the ground of the test bench respectively, and make sure that the ground of the test bench is connected to the power supply terminal. Then increase the test voltage to the specified value regularly, and keep it for 1 il. If there is no phenomenon, then slowly reduce the test voltage to zero and cut off the power supply. The test voltage should meet the following requirements: 501V between the output terminal and the shell; 1V between the power supply terminal and the shell; 1000V between the power supply terminal and the output terminal (I) Appearance inspection of the pneumatic transmitter: 1:26 indication inspection is carried out according to the provisions of Sections 21.1.-21.3. 26.1 (1 The transmitter is Input a 0.16 grade standard pressure gauge with a value of 0.16MP= (1.6kg/cm2). After adjustment, connect the pressure gauge to 0.13M (1.4g/a).
26.2 Adjust the pressure gauge with different positions and quantities.
26.2.1 Install the code plate according to the requirements of Section 22.2: 3
26.2.2 Adjust the zero position to create an output signal gauge pressure of 0.01%M1 (0.2kg[/mt]). 26.2.3 Add a code with a new upper limit value of the force to the code plate and make adjustments to make the output signal force 0.0981MPu (1.0kgf/cm2).
2F.2.4 Remove all the code plates and the output signal pressure should be restored to 0.0190M1% (0.2kg//mt). Otherwise, H3 26.2.2 rate of this paragraph force sudden adjustment, wear low ticket should not be too much, mM (0.Dkgl/m! 26.3 indicates that the calibration
will be the actual limit of the force of the transmitter to the test point, the output signal 26.3.1
represents the force value. See the following installation
determination of the force Bo
more than the method
(IF 76
The code disk adds the force value of each inspection starting point to the code, and outputs the actual pressure of the output signal. 26.3.2
: Forward and reverse strokes, each data avoidance
26.3.3 Calculate the accuracy of the target force value. The calculation formula is as follows: p
The accuracy of the target force value
3 should not exceed ±.5%
100% (the unit of treatment is MPL?
Product×100% (the unit of force is kgf/a)
26.3.4 Calculate the lookback error of the single receiving party, and the calculation formula is: pt
P-2×100%
(kgi/an\)
Wu Zhong:. ,. ——Respectively the actual value of the pressure gauge at the positive and negative strokes of the first calibration point. 4=(
The value is not greater than .5.
26.3.5 For the transmitter that meets the requirements of 25-20.3.4, calculate the accuracy of the flow measurement according to Appendix 4: 1. The value is not more than 4%,
27 Pressure error and sieve sealing test
271 The requirements of 23.1 and 23.2 are followed in the test path, 27.2 Net error test: Under the condition of the product being safe, the output signal of the transformer is guaranteed to be within the lower limit value.096MPa (.2kg/cm, .096.0081M (0.2-1.0kf4) per 1235Dkgl/m! 26.3 indicates that the test is to be carried out to the actual force limit of the transmitter. The output signal 26.3.1 indicates the force value. See the following method for determining the force (IF 76
The code disk adds the force value of each inspection starting point to the code, and outputs the actual pressure of the output signal. 26.3.2
: Forward and reverse strokes, each data avoidance
26.3.3 Calculate the accuracy of the target force value. The calculation formula is as follows: p
The accuracy of the target force value
3 should not exceed ±.5%
100% (the unit of treatment is MPL?
Product×100% (the unit of force is kgf/a)
26.3.4 Calculate the lookback error of the single receiving party, and the calculation formula is: pt
P-2×100%
(kgi/an\)
Wu Zhong:. ,. ——Respectively the actual value of the pressure gauge at the positive and negative strokes of the first calibration point. 4=(
The value is not greater than .5.
26.3.5 For the transmitter that meets the requirements of 25-20.3.4, calculate the accuracy of the flow measurement according to Appendix 4: 1. The value is not more than 4%,
27 Pressure error and sieve sealing test
271 The requirements of 23.1 and 23.2 are followed in the test path, 27.2 Net error test: Under the condition of the product being safe, the output signal of the transformer is guaranteed to be within the lower limit value.096MPa (.2kg/cm, .096.0081M (0.2-1.0kf4) per 1235Dkgl/m! 26.3 indicates that the test is to be carried out to the actual force limit of the transmitter. The output signal 26.3.1 indicates the force value. See the following method for determining the force (IF 76
The code disk adds the force value of each inspection starting point to the code, and outputs the actual pressure of the output signal. 26.3.2
: Forward and reverse strokes, each data avoidance
26.3.3 Calculate the accuracy of the target force value. The calculation formula is as follows: p
The accuracy of the target force value
3 should not exceed ±.5%
100% (the unit of treatment is MPL?
Product×100% (the unit of force is kgf/a)
26.3.4 Calculate the lookback error of the single receiving party, and the calculation formula is: pt
P-2×100%
(kgi/an\)
Wu Zhong:. ,. ——Respectively the actual value of the pressure gauge at the positive and negative strokes of the first calibration point. 4=(
The value is not greater than .5.
26.3.5 For the transmitter that meets the requirements of 25-20.3.4, calculate the accuracy of the flow measurement according to Appendix 4: 1. The value is not more than 4%,
27 Pressure error and sieve sealing test
271 The requirements of 23.1 and 23.2 are followed in the test path, 27.2 Net error test: Under the condition of the product being safe, the output signal of the transformer is guaranteed to be within the lower limit value.096MPa (.2kg/cm, .096.0081M (0.2-1.0kf4) per 1235
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