I contemplate using one or more of your 1730 wireless digital indoor/
outdoor thermometers to monitor a water-filled hydronic heating installation 
against freezing. I propose to apply the outdoor sensor: a) to the
surface of a 4 inch cast iron return pipe or if a) is not possible then
b) to the surface of a 3/4 inch copper return pipe.

My questions:
1) what distance (if any) from the cast iron or copper pipe respectively
is required to permit i) accurate temperature reading and ii) useful wireless 
transmission.

2) would the outdoor sensor be damaged by being subjected to 180 F. degree
temperature when the heating system was activated or should that sensor
be removed prior to such activation.

Thank you for your help. If you answer my questions, yours will be the
most responsive "product support" department in memory.

Sincerely yours
Ernst J. Meyer MD
174 School Street
Belmont MA 02478
617-489-1043