Hello again sir Bob! I found out that the thermistor I have takes 1.5 minutes to register a to= tal change in temperature. But why does in my thermistor circuit, with a LCD readout, why does it ta= ke more than 5 minutes for the reading in the LCD to stabilize? Please help me. Bob Ammerman wrote: Thermal 'circuits' are very similar to electrical circuits. You can use a= lot of the same analysis tools (like ohms law, kirchoffs law, etc) by jus= t changing the terminology: Masses(things that store heat) =3D=3D capacitors Connections between masses =3D=3D resistors Temperatures =3D=3D voltages Heat flows =3D=3D currents So, for example if you know the thermal mass of the thermistor (its pseudo-capacitance) and the thermal resistance of its connection to the i= tem being measured (the pseudo-resistance) you can compute the corresponding time constant RC (just like in an electrical circuit). Bob Ammerman RAm Systems (contract development of high performance, high function, low-level software) -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu ____________________________________________________________________ Get free email and a permanent address at http://www.netaddress.com/?N=3D= 1 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu