Analysis of temperature control instrument system fault, notice first two points: the system applied electric meter measuring instrument, instructions, control, This system instrument measuring often lag is bigger.
 
(1) temperature control system is indicating value suddenly to a maximum or minimum, general for the instrumentation system failure. Because the temperature measuring instrument system lags behind larger, won't happen suddenly changes. At this time the failure causes of thermal resistor is more thermocouples, wires, compensation conductor or transmitter amplifier failure caused.
 
(2) temperature control instrument systems instruc-tions appears rapid oscillation phenomena, PID control parameter improper adjustment.
 
(3) temperature control instrument systems instruc-tions appear sharply slow wave, probably due to the change process operation, such as when process operation, no changes, probable is instrumentation control system itself fault.
 
(4) temperature control system itself the failure analysis steps: check whether changes, input signal regulator input signal not change, the regulator movement, the regulator membrane head diaphragm leakage, Check regulator locator input signal whether changes, the input signal not change, the output signal changes, the locator have fault; Check the locator input signals have change, look for changes in adjustment output, if not change, input adjuster, this is a regulator output variation of fault. Itself, 2. Pressure control instrument system failure analysis steps

(1) pressure control system instrumentation instructions appear rapid oscillation fluctuate, first check process operation without change that is mostly process operation, and regulator PID parameters setting bad cause.
 
(2) pressure control system instrumentation instructions appear dead line, process operation instructions or not to change the pressure changes, general fault appeared in pressure measuring system, first check the measuring lead pressure ductal system whether have blocked the phenomenon, not plugging, check pressure transmitter output system for changes, have change, fault out on the controller measurement indicator system