Method for improving filling accuracy of peristaltic pump：
1. Using the time timer to control the filling amount, this method is easy to implement, but the error is also large. The main reasons are the influence of temperature and the influence of program structure. The single-chip microcomputer works by the frequency output of the crystal oscillator, and the temperature has an effect on the crystal oscillator frequency. A good crystal oscillator can minimize the impact, but it cannot be eliminated. This influence directly determines the size of the timer time base in the single-chip microcomputer, as a result, the set time length is affected, resulting in the same working time of each peristaltic pump, resulting in errors. In addition, it is not advisable to use the program to accurately generate the time value. During work, the influence of various interrupt operations will cause time errors, and this error is unpredictable and cannot be compensated.
2. Control the filling volume by the number of pulses. This method can ensure that the total number of angles operated by the peristaltic pump for each distribution is the same, and the filling accuracy is much improved compared to the time control method. However, due to the pulsation phenomenon when the peristaltic pump transmits the liquid, although the total operation angle can be controlled by the number of pulses, the instantaneous flow rate is in the peak or trough of the pulsation or a certain flow rate in the middle when the pump is stopped. The location is inconsistent after an allocation. In this way, the effect of the distribution of liquid volume will be relatively small due to the different stop positions of the rollers each time, mainly because it will have a great impact on the distribution of small liquid volumes.
3. Use angle control technology to control filling volume. This method adds the angle control technology during shutdown on the basis of using the number of pulses to control the filling volume to ensure that the peristaltic pump rollers are in the same position every time the peristaltic pump is stopped, thus eliminating the impact of the peristaltic pump pulsation on the filling volume. It has a very obvious improvement for the filling of small flow.