An open loop control system requires:

An open loop control system operates based on predetermined conditions without feedback from the actual output. This means that once the system is activated, it runs through its program regardless of the outcome, which inherently necessitates constant monitoring and operator attention to ensure that the system is functioning as intended and to make adjustments if necessary.

Since there is no feedback mechanism to correct any deviations in performance, the operator must be vigilant to prevent issues such as inefficiencies or malfunctions. This contrasts with closed loop systems, where feedback allows for automatic adjustments, effectively reducing the need for direct oversight.

In this context, the other choices do not inherently define the requirements for open loop control systems. While some may appear relevant in certain uses, they do not align specifically with the fundamental characteristics of open loop control. For instance, the need for accurate sensing devices or minimized dead time is more critical in closed loop systems where feedback plays a key role in system adjustments. Similarly, the use of transducers and recorders is not a mandatory requirement for the operation of an open loop system.