10.02.2013 Views

Sensor Installation Handbook Preface 3rd edition - Siemens ...

Sensor Installation Handbook Preface 3rd edition - Siemens ...

Sensor Installation Handbook Preface 3rd edition - Siemens ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Principles of operation<br />

64<br />

Switching devices<br />

On/off<br />

Changeover<br />

3-position<br />

Multi-stage<br />

Dynamic switching differential<br />

Setpoint<br />

Switching devices<br />

Thermostats<br />

Hygrostats<br />

Pressure switches<br />

Where a switching device such as a thermostat is installed in a system,<br />

it should be noted that the temperature swing will be wider than the<br />

switching differential of the thermostat. The thermostat operates at the<br />

switching points specified in the data sheet (static switching differential),<br />

but the inertia of the system (residual heat, dead time etc.) causes the controlled<br />

variable to overshoot or undershoot. The finally measurable temperature<br />

swing (the dynamic switching differential) will therefore always be<br />

wider than the static switching differential of the thermostat.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!