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Thu, 16 Dec 1999 13:59:49 EST |
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Jim -
The simplest approach is the direct approach. Regarding conveyor speed, mark
off a measured length on the on-load (or off-load) and time how long it takes
a mark on the conveyor (or a link or pin) to cover the distance. Calculate
the speed and compare it to the setpoint. Most ovens have closed-loop
conveyor speed control but it is a good idea to test it.
The way I used to measure accuracy of temperature was to attach a
thermocouple to the the PDI controller (or you can use the inputs for
on-board profile tracking your oven might have come with) and place the
thermocouple first into a beaker of ice and then into a beaker of boiling
water. The temperature measured by the machine should be 0 deg. C and 100
deg C respectively.
I suppose there are fancier, more "academic" approaches, but this is
practical, simple, economical and can even be incorporated as part of your
ISO-9002 procedures.
Phil Zarrow
ITM, Inc.
Durham, NH USA
www.ITM-SMT.com
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