low cost temp sensor

[Martin Czech]

For obvious reasons (my last mail) I need a very good thermometer.
Should have 0.1 K resolution and fast settling time.

You can use a bipolar transistor for a cheap temperature sensor (-2mV/K).
These come in plastic packages.

Now, I would like something smaller and with lower temperature resistance
to get a faster setling time.

A 1N4148 Diode could be used.

Do you think that the diode will show much error due to parasitic
resistance in a temperature range from 0C to 90C ?

May be a metal can package transistor would do.

Or should I better consider a LMxxx temperature sensor (not that
expensive).

What about long time drift? I guess the LMxx parts have a spec for this,
whereas my homebrew are unknown ....

Any ideas?

m.c.