TMP03 is a Serial Digital Output Thermometer
http://www.analog.com/static/imported-files/Data_Sheets/TMP03_04.pdf

I have used this Temperature sensor for years and
to diverse applications of temperature control.
It provides 1 wire digital output in a pwm form.
The Up time T1 and the Low time T2 of the waveform
give the actual temperature reading as
T = 235 - (400*T1/T2) in °C, or
T = 455 - (720*T1/T2) in °F
This ratiometric measurement of the up/down count
times is precice enough and gives accuracy about ±1°C.
The device in TO92 package is small enough to fit
almost everywhere, but not to the pipe of 4mm of
the current project.
I'll suggest to the manufacturer to provide a wider
pipe at 8-10mm to install this thermometer with the
insulation.

Thanks for your support
K.L.Angelis