2
\$\begingroup\$

My boss talked about those sensors today. I have no experience with either of them. Can someone please explain the theory and advantages/disadvantages of each type?

\$\endgroup\$
3
\$\begingroup\$

When Inductors or capacitors are used in tuned LC tank circuits they tend to drift with temperature. It is not very precise for a high quality thermometer, so diodes tend to be used for high volume thermal sensors. THermal resistors or thermistors are still in use as well, which cover a much broader selection for various sensitivities.

For every application where temperature compensation is required such as for sensitive LC tuned filters or oscillators. Normally ceramic parts can be made with C0G material which are temperature stable or negative positive zero ppm/deg C aka NP0 often mis-labelled as NPO as in (n-p-oh) but was originally specified as NP Zero temp-coeff. There are many compensation values , but typically more negative ppm/deg C.. so you may find P300 to N1500 ceramic caps in the small standard value range for compensation.

Apart from magnetometers which use LC sensors or proximity sensors and using ceramic caps as vibration sensors, I have never heard of people using LC components for accurate thermal sensors.

Can you clarify what type of materials you boss was referring for temperature sensors? May I suggest re-phrasing the question.

\$\endgroup\$
  • \$\begingroup\$ He talks about NON touching thermo sensor. Sensing an object 2 inch in front of sensor. The object is 0.02 inch thick. The sensor should not take any reading behind the object. There are so many things that I don't know. I really want to provide more information, but I don't understand the information. \$\endgroup\$ – Superhero Aug 8 '12 at 5:13
  • \$\begingroup\$ there are non touching thermal sensors based on IR emissions. Those are used to get feedback on those microprocessor controlled inductor heaters. \$\endgroup\$ – Standard Sandun Aug 8 '12 at 8:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.