Homebrew PCBs

Just repeated the temperature measurements using a different 
thermocouple.  Temperatures at one inch from the end of the rollers 
are in the 285 F to 290 F range.  Temperatures at the middle of the 
rollers are in the 295 F to 310 F range.  My temperature measurements 
vary, possibly indicating the heating mechanism is cycling off and on.

These temperatures don't sound very high to me.  Yet my laminator 
works like a charm.  Perhaps it is telling us that the optimum 
transfer temperature is lower than we might think.

--- In Homebrew_PCBs@yahoogroups.com, "Radra" <infositeus@y...> wrote:
> 
> I measured the roller temperature as 287 degrees Fahrenheit (142 
> degrees Celsius).  This  measurement was rather tricky to make.  I 
> fed the thermocouple into the H200 laminator and attempted to turn 
it 
> off just as the thermocouple junction entered the rollers.  Can't 
> actually see to verify the thermocouple is properly placed so 
> measurement may be low.  Repeated measurement several times and 
> always found temperatures to be in the high 270s or low 280s ranges.
> 
> According to a prior post, the temperature should have been 361 F 
> (183 C).  There is a large discrepancy here.  I might repeat the 
> measurement tomorrow using a different thermocouple.  Perhaps 
someone 
> can suggest a better measurement technique.
> 
> Lyman