Fig. 1. Working principle of engine thermostat

Fig. 2. Measurement principle of thermostat valve lift

Fig. 3. Structure diagram of thermostat testing system

Fig. 4. Photo of thermostat testing system

Fig. 5. Relation curve between lift and temperature of Jiefang J6 thermostat（fitting from temperature stability test of single thermostat）

Fig. 6. Relation curve between lift and temperature of Jiefang J6 thermostat（fitting from performance consistency test of multiple thermostats）