Calibration method for intelligent flow integrator

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Intelligent flow accumulators can be used in conjunction with various flow sensors such as turbines, vortex flow meters, orifice plates, nozzles, electromagnetic flow meters, target flow meters, metal rotor flow meters, Anemometers, and rotary centrifugal flow meters, to measure and accumulate the mass flow rate and volume flow rate of gases, liquids, saturated steam, and superheated steam. With the widespread use of intelligent flow accumulators, it has become increasingly important to calibrate them. Below, taking Changhui Instrument’s YR-GFK intelligent flow accumulator as an example, we explore its calibration methods. http://yunrun.com.cn/upload/201611/25/201611251601448036.jpg 1. Calibration methods for the main components: The calibration of the YR-GFK intelligent flow meter involves correcting the conversion errors in various aspects such as the flow input, temperature compensation input, pressure compensation input, instant flow display, and instant flow transmission output that are built into it. 1.1 Calibration of the temperature compensation input ① Configure the temperature compensation input channel of the flow totalizer correctly. The temperature compensation input signal for the YR-GFK intelligent flow totalizer can be a thermistor, thermocouple, current, or voltage signal; the type of temperature compensation input signal can be switched through the instrument’s secondary parameters. Before calibration, it is necessary to configure the relevant parameters for temperature compensation according to the requirements of on-site use. The secondary parameters related to the instrument and temperature compensation inputs are as follows: T-dp is the decimal point for temperature compensation display; T-n is the input type for temperature compensation; T-b is the zero offset for temperature compensation (adjusted only during calibration); T-K is the range scaling factor for temperature compensation (adjusted only during calibration); T-L is the lower limit of the temperature compensation range; T-H is the upper limit of the temperature compensation range. Taking a Pt100 input as an example, the parameter settings are as follows: T-dp=1, T-n=14, T-b and T-K remain at their factory default values, T-L=-200, and T-H=650. ②Temperature compensation input calibration device and wiring diagram: The conversion error of the temperature compensation input (Pt100 platinum resistor) of the YR-GFK intelligent flow integrator is calibrated using a standard resistance box ZX54; the wiring is shown in Figure 2 ； The conversion errors of thermocouples as well as current and voltage are calibrated using a high-precision process calibrator acting as a signal generator; the circuit connections are shown in Figures 3 to 6. http://yunrun.com.cn/upload/201611/25/201611251122098036.png Figure 1: Wiring diagram of the YR-GFK intelligent flow meter. http://yunrun.com.cn/upload/201611/25/201611251211304286.png Figure 2: Calibration wiring when the temperature compensation input for the YR-GFK intelligent flow meter is a thermal resistor. http://yunrun.com.cn/upload/201611/25/201611251212555692.png Figure 3: Calibration wiring when the temperature compensation input for the YR-GFK intelligent flow meter is a thermocouple. http://yunrun.com.cn/upload/201611/25/201611251215021786.png Figure 4: Calibration wiring when the temperature compensation input for the YR-GFK intelligent flow meter is a voltage (V). http://yunrun.com.cn/upload/201611/25/201611251216486473.png Figure 5: Calibration wiring when the temperature compensation input for the YR-GFK intelligent flow meter is a voltage (mV). http://yunrun.com.cn/upload/201611/25/201611251217367255.png Figure 6: Calibration wiring when the temperature compensation input for the YR-GFK intelligent flow meter is a current (mA). ③ Method for calibrating the temperature compensation input: As shown in Figure 2, resistive signals Rt1, Rt2, Rt3, Rt4, and Rt5 are inputted through terminals 22#, 23#, and 24#. The theoretical temperature values t1, t2, t3, t4, and t5 are obtained from a Pt100 thermometer. The temperature compensation values t′1, t′2, t′3, t′4, t′5 (for the upper range) and t″1, t″2, t″3, t″4, t″5 (for the lower range) will be displayed on the intelligent flow meter’s temperature compensation display. The difference between the displayed values during the upward and downward strokes and the theoretical temperature values at the corresponding points is considered the error Δt. The largest of these errors at each measurement point is identified as Δtmax. The temperature compensation input conversion error for the flow meter is then calculated, where tH represents the upper limit of the temperature compensation range for the flow meter, and tL represents the lower limit of that range. ④Example of temperature compensation for input calibration: Taking the temperature compensation input of a flow integrator, which is a Pt100 platinum resistor (with a measurement range of 0–320°C), as an example, calibration is carried out using the method described above. This yields a set of data from which the temperature compensation conversion error can be determined. The temperature compensation input uses calibration data for a Pt100 platinum resistor (measurement range: 0–320°C). http://yunrun.com.cn/upload/201611/25/201611251311428973.png ⑤ Result processing: The conversion error of the temperature compensation input can be determined from the table above; it is possible to assess whether it meets the error requirements specified for intelligent flow accumulators. If deviations are detected during calibration, the secondary parameters T-B and T-K of the instrument can be adjusted until the requirements are met. 1.2 Calibration of the pressure compensation input ① Configure the pressure compensation input channel of the flow totalizer correctly. The pressure compensation input signal for the YR-GFK intelligent flow totalizer can be in the form of current or voltage signals; the type of pressure compensation input signal can be switched via the instrument’s secondary parameters. Before calibration, it is necessary to configure the relevant parameters for the pressure compensation input according to the requirements of on-site use. The secondary parameters related to the instrument and pressure compensation input are as follows: P-dp – the decimal point for the pressure compensation display; P-n – the type of input for pressure compensation; P-b – the zero-point adjustment for pressure compensation (adjusted only during calibration); P-K – the range ratio for pressure compensation (adjusted only during calibration); P-L – the lower limit of the pressure compensation range; P-H – the upper limit of the pressure compensation range. As an example, assuming that the pressure compensation input signal is 4-20mA with a range of 0-1.6 MPa, the parameter settings would be: P-dp=3, P-n=28, P-b and P-K remain at their factory default values, P-L=0.000, and P-H=1.600. ② Equipment and wiring diagram for calibrating the pressure compensation input: The conversion error in the pressure compensation input of the YR-GFK intelligent flow integrator is calibrated using a high-precision process calibrator as a signal generator; the wiring is shown in Figures 7 and 8. http://yunrun.com.cn/upload/201611/25/201611251313089442.png Figure 7: Calibration wiring for the YR-GFK intelligent flow meter when the pressure compensation input is in current (mA) form. http://yunrun.com.cn/upload/201611/25/201611251314190536.png Figure 8: Calibration wiring for the YR-GFK intelligent flow meter when the pressure compensation input is in voltage (V) form. ③ Method for calibrating the pressure compensation input: As shown in Figure 7, current signals P1, P2, P3, P4, P5 are fed in through terminals 15# and 19#. The pressure compensation values will be displayed as P′1, P′2, P′3, P′4, P′5 (for the upward stroke) and P″1, P″2, P″3, P″4, P″5 (for the downward stroke). The difference between the displayed values during the upward and downward strokes and the theoretical pressure values at the corresponding points is considered the error ΔP. The largest of these errors at each measurement point is identified as ΔPmax. This value represents the temperature compensation input conversion error of the flow meter; where PH is the upper limit of the pressure compensation range for the flow meter, and PL is the lower limit of that range. ④Result processing: The pressure compensation input is calibrated data in the form of 4-20mA (measurement range: 0-1.6 MPa). The conversion error of the pressure compensation input for the flow totalizer can be determined from the table above; based on the technical requirements regarding errors in intelligent flow totalizers, it is possible to determine whether such an error is acceptable. When deviations occur during calibration, the secondary parameters P-B and P-K of the instrument can be adjusted until the requirements are met. 1.3 Calibration of the flow input ① Properly configure the flow input channel of the flow meter. The YR-GFK intelligent flow meter supports three types of flow input signals: current, voltage, and frequency. The type of flow input can be modified through the instrument’s secondary parameters, allowing easy adaptation to various flow sensors commonly available on the market. Before calibration, the parameters related to flow input must be correctly configured in accordance with the technical requirements of the on-site flow sensor. The secondary parameters related to the flow input for the instruments are as follows: F-dp – the decimal point for displaying flow rate (linear, differential pressure); F-n – the input type for flow rate (linear, differential pressure); F-b – the zero offset for flow input (adjusted only during calibration); F-K – the range scaling factor for flow input (adjusted only during calibration); F-L – the lower limit of the flow input range; F-H – the upper limit of the flow input range. As an example, taking the differential pressure transmitter of a differential pressure flow meter that outputs 4-20mA within a range of 0-40kPa, the parameter settings are as follows: F-dp=2, F-n=28; F-b and F-K remain at their factory default values; F-L=0.00, F-H=40.00. ② Equipment for calibrating flow input and wiring diagrams: The conversion error in the flow input of the YR-GFK intelligent flow integrator is calibrated using a high-precision process calibrator as a signal generator. The wiring is shown in Figures 9, 10, and 11. http://yunrun.com.cn/upload/201611/25/201611251422036786.png Figure 9: Calibration wiring for the YR-GFK smart flow meter when the flow input is in the form of frequency (Hz). http://yunrun.com.cn/upload/201611/25/201611251423038661.png Figure 10: Calibration wiring for the YR-GFK smart flow meter when the flow input is in the form of current (mA). http://yunrun.com.cn/upload/201611/25/201611251424000067.png Figure 11: Calibration wiring for the YR-GFK smart flow meter when the flow input is in the form of voltage (V). ③ Method for calibrating flow input errors: Connect the wires according to the flow input wiring diagram; send frequency signals from terminals 31# and 32#, or send current/voltage signals F1, F2, F3, F4, F5 from terminals 13# and 14#. The flow input values will be displayed as F′1, F′2, F′3, F′4, F′5 (for the upward stroke) and F″1, F″2, F″3, F″4, F″5 (for the downward stroke) on the display of the smart flow meter. The difference between the displayed values during the upward and downward strokes and the theoretical flow rate values at the corresponding points is considered the error ΔF. The largest of these errors at each measurement point is identified as ΔFmax. The conversion error of the flow input value in the flow counter is then calculated as follows: FH represents the upper limit of the flow input range for the flow counter, while FL represents the lower limit of that range. ④Calibration data output by the differential pressure transmitter of the differential pressure flow meter (4-20mA, range: 0-40 kPa) for flow input calibration. 1.4 Calibration of instantaneous flow: The instantaneous flow value displayed by the flow integrator is influenced by the flow input, compensation signal input, mathematical model, and K coefficient; to obtain an accurate display of instantaneous flow, it is necessary to properly program and configure the flow integrator. ①Program the flow totalizer correctly. Before programming the instrument, it is necessary to carefully read the instructions for the flow totalizer (refer to them) before proceeding with the programming. Here is an example illustrating the programming process of the YR-GFK intelligent flow integrator: It measures a certain gas using a orifice plate, accepts differential pressure input, performs pressure and temperature compensation, and does not provide an instantaneous flow output; flow accumulation is prevented when the differential pressure is less than 10 kPa. It features RS485 communication. The relevant system data are as follows: Differential pressure transmitter: 4-20mA, range: 0-80KPa; Pressure transmitter: 1-5V, range: 0-3MPa; Temperature transmitter: 4-20mA, range: 0-300℃. Operating point atmospheric pressure (PA): 0.08MPa. Density at standard conditions: ρ20=2Kg/m3. When the operating pressure (compensation pressure) P=3MPa and the operating temperature T=300℃, the maximum flow rate M=100t/h. Instrument selection: YR-GFK802-800-AAA-HL-2P. According to the formula: ② The parameter settings are as follows: a. Enter the secondary parameter settings; b. Exit the secondary parameter settings and enter the primary parameter settings; c. Instrument calibration – instant flow rate verification. 2. Summary: For ordinary intelligent flow meters, calibrating the four main parameters namely temperature compensation, pressure compensation, flow input, and instant flow rate transmission output is sufficient to meet their operational requirements. If necessary, functional checks such as the alarm function, cumulative error, clock, and density calculation can be performed.