Charging is the process of transferring a quantity of liquid over a specified period. Charging accuracy error refers to the measurement of each charge quantity after multiple charging. The formula is: charging accuracy =(maximum-minimum)/ average value. Therefore, to ensure the consistency of charging quantity is to improve the accuracy of charging. The stepper motor is easy to control the Angle and the working speed is not affected by the load, so a more accurate open-loop control system can be made. Therefore, the general charging system is driven by the stepper motor.
The technology currently used in the
Peristaltic Pump charging market is also different, now mainly talks about the characteristics of various technologies.
1: Use a time timer to control the charging amount. This method is easy to achieve, but the error is also large. The main reason is the influence of temperature, the influence of program structure. SCM as the crystal frequency output work, temperature affects the crystal frequency, good crystal vibration can minimize the impact, but can not eliminate. This influence directly determines the size of the time standard of the timer in the single-chip microcomputer and affects the set time. Therefore, the working time of each peristaltic pump is inconsistent, leading to errors. In addition, the use of programs to accurately generate time numbers is not desirable. When working, the effects of various interruptions may result in unpredictable and irreparable time errors.
2: use pulse number to control the amount of charge. By using this method, the total Angle of the peristaltic pump is the same, and the charging accuracy is much higher than that of the time control method. However, because the peristaltic pump has a pulsation phenomenon when transmitting liquid, the total working Angle can be controlled by pulse number, but the instantaneous flow rate is unchanged at the peak or valley or middle flow rate when stopping. That is, when the wheel stops, the position is not consistent after the previous allocation has been completed. This will result in an allocation error because each wheel stops at a different position. Compared with the large traffic distribution, the distribution error mainly affects the small traffic distribution.
3: use Angle control technology to control the amount of charge. In this method, the charging quantity is adjusted by pulse number, and the Angle control technology is added when the machine is stopped so that the peristaltic pump wheel is in the same position when the machine is stopped, so that the influence of the pulsation of the peristaltic pump on the charging quantity is eliminated, and the charging with small flow rate is greatly improved.
The above three charging technologies are open-loop control and do not consider the flow attenuation factor of the
Peristaltic Pump Hose. The actual work should be calibrated regularly to achieve higher charging accuracy.
In addition, peristaltic pump charging can also be installed with non-contact sensors (infrared, capacitance sensors, etc.) that can measure water level height, forming a closed-loop charging system, eliminating the influence of hose flow attenuation, to maintain the consistency of charging quantity in the hose life.
Contact;Ella Xu Phone:15633705132 Email:sales01@crpump.com
