Oil dampers have characteristics of temperature and speed dependence.
In general, the viscosity of liquid changes greatly with temperature. The viscosity decreases as the temperature rises and the viscosity rises as it goes down. This phenomenon is called a temperature characteristic. The damper has the property that the torque changes with the difference in temperature. When the temperature is higher, the movement is faster, and when the temperature is lower, the movement is slower.
As an example, here is the graph of characteristics of temperature for the TD 14. At 23 degrees, the closing time is 6.5 seconds, and at 40 degrees, the closing time is 6 seconds; even at 0 degrees, it is 7.3 seconds. If the temperature goes up and the viscosity of the oil drops, it gets faster but it does not go up much.
Also, as the speed goes up the torque increases and we call it speed dependence. The infinite angle damper takes torque with the shear resistance generated by agitating the oil, and this shear resistance increases in proportion to the speed.
This is a speed dependence graph of the TD62. You will see that the torque increases as the speed increases. In other words, since it cannot be set to the slow down speed assuming that the torque is not matched. When you choose dampers to work for the toilet seat etc. you should consider the speed dependence of the damper.
