LM35 Temp Sensor Distance Issue
Have you 'scoped the output? The LM35 is susceptible to EMI (which you have addressed with shielded cable) and load capacitance - which may be an issue. If there is instability due to load capacitance (>50pF) you can isolate this capacitance with a series resistor. If external EMI is still an issue, an RC damper can be added. Both effects are addressed on p7 (figs 3 &amp; 4) of the datasheeet.