At present, many cars are equipped with in-tire sensors to check the internal working pressure of the tire. The tire pressure will be displayed immediately on the instrument table, or it can be accurately measured with a tire pressure meter, which can be divided into compass tire pressure meters, digital display tire pressure meters and alarm tire pressure meters. The digital tire gauge also shows the tire pressure at the same time, while the alarm tire gauge only works when the tire pressure is too high or too low.
The compass tire pressure gauge, it is necessary to load the dial said reading value to understand the tire pressure, generally divided into the inner ring and the outside, the outside is the British unit psi, the inner ring enterprise is kg/cm^2, their calculation between 14.5psi=1.02kg/cm2=1bar. Generally look at the inner ring, because the minimum scale of the inner ring is 0.1, the minimum scale of the outside is 1, and the inner ring is more accurate.
When the tire pressure is too high on the dashboard, generally higher than 345kpa gradual high pressure alarm, the tire must be deflated to repair about 335kpa to eliminate the following high pressure alarm: If the tire pressure is too low, generally less than 175kpa gradual low voltage alarm, it must be repaired to about 230kpa above to eliminate the low voltage alarm. If the alarm of rapid tire pressure relief occurs, indicating that the tire pressure is reduced by more than 30kpa within one minute, then the problem inventory must be carried out, and the alarm will be eliminated only when the whole car is turned off.
If there is no tire pressure detection system or tire pressure gauge, you can estimate the tire standard pressure, that is, carefully observe the tire deformation level to distinguish the tire standard pressure. There are two ways to estimate the standard pressure of the tire, the first is according to the car has been driven on the sand road, look at the distance between the edge of the sand scratch and the tire shoulder, if the edge is just in the tire shoulder, or close to the tire shoulder, the tire pressure is just right.
If the edge of the involved surface is far from the tire shoulder, the tire pressure is too high, which will cause the tire to grasp the land and reduce the reliability; If the side edge of the involved surface is turned over the shoulder, it indicates that the tire pressure is low, the fuel consumption will be large, the hot will be aggravated, and the low voltage tire will easily lead to a flat tire.
The second is to carefully observe the total number of patterns on the tire surface to distinguish the tire pressure. A grain in the middle of two gaps. If all the tire pressure is normal, the total number of tire road markings is 4 to 5, more than five indicates that the tire pressure is slightly low, less than four indicates that the tire pressure is too high.