On Sunday, December 17, 2017 at 3:17:57 PM UTC-5, Dave Nadler wrote:
On Sunday, December 17, 2017 at 3:15:03 PM UTC-5, wrote:
(old) Cambridge varios used 2 thermistors in line to sense flow.

IIRC 3 thermistors; Raouf added a non-sensing thermistor in the middle
to increase temperature differential. Earlier units like Crossfell used 2.

One early version I took apart had 2. Later ones may have added a center one to help with linearity.
I recall hearing that Raouf made more money selling flow sensors to computer makers than he ever did making soaring instruments.
UH