It may be because the peristaltic pump relies on the rebound of the pump tube to suck in the liquid. The rebound of the peristaltic pump hose takes a certain amount of time. The more viscous the liquid is, the longer it takes to rebound.

　　Therefore, when the rebound time of the pump is less than the displacement time of 1 wheelbase of the peristaltic pump (if the runner of the peristaltic pump is composed of 2 wheels, the arc of the 2 wheelbases is 180 degrees. When a runner rotates half a circle, it makes a circular motion The time required is a wheelbase displacement time, the higher the speed, the shorter this time will be).

　　The relationship between the flow rate of the peristaltic pump and the speed is a linear increase. If the time required for a rebound is greater than the time of wheel pitch displacement, that is, the hose of the peristaltic pump is pressed again by the runner before it has fully rebounded, then the flow rate generated by the peristaltic pump per revolution will be completely rebound than the pump tube. When the flow rate is small.

　　Of course, if the rotation speed of the peristaltic pump is fixed, and the lotion pump head, then each revolution is also fixed.