TY  - JOUR
AB  - Well designed stable reflow ovens and
wave machines can be operated at low rates of the inerting gas. One problem is that at the lowest
flow rate settings changes in room draughts and in external venting conditions can affect the
internal oxygen levels unless the flow rates are altered. The internal oxygen levels can drift or
suddenly alter. This generally means that the ovens are operated at higher flows than necessary
in order to ensure steady operations below some desired oxygen level without excessive operator
intervention. A closed‐loop control system using the output of internal oxygen meters
to vary the flow rates set by mass flow meters is one way to ensure steady operation. One such
system — NITRAPILOT™ control system—has been developed by BOC Gases as a stand
alone system that can be added to existing equipment. The results of small‐scale and
production level testing on this system are described in the present paper. Reduced flow rates
can be achieved for stable set point oxygen levels at critical locations. An equally significant
benefit, particularly when used in conjunction with data logging, is that the system assists in
statistical process control since it ensures, monitors and logs compliance with process recipes
without operator intervention.
VL  - 9
IS  - 1
SN  - 0954-0911
DO  - 10.1108/09540919710777752
UR  - https://doi.org/10.1108/09540919710777752
AU  - Saxena N.
AU  - Precious C.
AU  - Carr A.
AU  - Adams S.
PY  - 1997
Y1  - 1997/01/01
TI  - Closed Loop Control of Atmospheres for Soldering
T2  - Soldering & Surface Mount Technology
PB  - MCB UP Ltd
SP  - 8
EP  - 10
Y2  - 2024/04/18
ER  -