Turn on and cut function details: The table shows the turn on and cut situations as pointer moves deasil, and the function is opposite while the pointer moves widdershins.

表中描述的开关功能是表示：仪表压力指值时所具有的开关功能，即压力指从值开始顺时动时的开关状态，当压力指逆时转动时，实现的开关功能相反。