Step response time of control system

[kampftrimker]

Homework Statement

I'm having a slight problem with the question below.

A temperature control process has a first-order response with a step response time of 12 seconds. In selecting a temperature sensor for the control system for the process, for what maximum value of sensor time-constant would you be looking?

My question is what is step response time?

Homework Equations

The Attempt at a Solution

Is it the time the process reaches its maximum value, if so then would the time constant (of the process) be
t = 12/5 =2.4 s

Thanks
Mick

 

[cpscdave]

Take a look at: http://en.wikipedia.org/wiki/Step_response

If I recall correctly step response is the amount of time that the system takes to reach its steady state (within 10%).

 

[donpacino]

Take a look at: http://en.wikipedia.org/wiki/Step_response

If I recall correctly step response is the amount of time that the system takes to reach its steady state (within 10%).

That is the settling time of the step response.

The step response is how a system responds to an instantaneous change in input.

there are a few other attributes of a step response such as rise time and percent overshoot.

 

[donpacino]

Homework Statement

I'm having a slight problem with the question below.

A temperature control process has a first-order response with a step response time of 12 seconds. In selecting a temperature sensor for the control system for the process, for what maximum value of sensor time-constant would you be looking?

My question is what is step response time?

Homework Equations

The Attempt at a Solution

Is it the time the process reaches its maximum value, if so then would the time constant (of the process) be
t = 12/5 =2.4 s

Thanks
Mick

I believe your solution is correct

 

[kampftrimker]

Thanks for the replies, they have helped me understand what is going on.

Thanks again

Mick