Calculation sequence
Step-by-step method
- Confirm actual verified travel percentage.
- Normalize elapsed time to a full stroke.
- Compare absolute deviation with the user-entered screening tolerance.
MechanicalBeginnerControls
Actuator Stroke-Time Calculator
Normalize a measured partial actuator movement to an equivalent full-stroke time and compare it with rated time.
Why it matters: Stroke time affects sequence timing, stability, safety response, and economizer operation.
Calculated result
Engineering evaluation
Equivalent full-stroke time (tf)90 s
- Deviation from rated stroke time (δt)
- 0 %
Engineering interpretation
The measured movement corresponds to 90 s full stroke, 0% relative to the entered rating and 20% screening tolerance.
Important limitations
- Stroke time varies with load, torque, pressure differential, spring return, power supply, control signal, linkage, and endpoint definition.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
tf = t·100/X
δt = (tf−tr)/tr×100
compare |δt| with Tol
Current substitution
tf = 90×100/100 = 90 s; δt = (90−90)/90×100 = 0%; Tol = 20%.
Equation legend
Inputs and calculated quantities
- X
- Verified travel — %
- t
- Measured elapsed time — s
- tr
- Rated full-stroke time — s
- Tol
- Entered allowable stroke-time deviation — %
- tf
- Equivalent full-stroke time — s
- δt
- Deviation from rated stroke time — %
Applications
How this calculation is used
Building design
Document required actuator timing.
Construction
Check linkage, feedback, and power supply.
Commissioning
Calculate equivalent full-stroke time from a verified partial or full movement.
Quality controls
Assumptions and limitations
Assumptions
- Entered data describe one stable operating condition and use consistent measurement boundaries.
- Time, energy, and performance values are representative of the stated interval.
Limitations
- This is a preliminary evaluation and commissioning-support tool, not an automatic acceptance determination.
- Project sequences, manufacturer data, tariffs, codes, and professional review remain controlling.
Field use
Verification procedure
- Confirm the operating mode, test boundary, and instrument calibration.
- Collect simultaneous readings or a documented trend interval.
- Compare the result with the approved sequence, submittal, and project criteria.
Common engineering mistakes
- Combining measurements from different operating modes or time intervals.
- Ignoring sensor uncertainty, trend sampling, or the defined equipment boundary.
Technical basis
References and source standards
- International Society of Automation ResourcesControl, instrumentation, alarm, and automation practice context; project sequences and current standards remain controlling.
- ASHRAE Handbook—HVAC Systems and EquipmentHVAC equipment, central-plant, air-system, and control-performance context; verify the licensed current edition during professional review.
- NIST Measurement and Calibration ResourcesFederal measurement, calibration, timing, and unit-system context.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement