http://www.globalw.com/downloads/WQ/WQSensormanual.pdf

500kB

"All Global Water water quality sensors produce a 4-19 mA output
signal. 4-19 mA is an industrial standard signal for process control
monitoring"

It's not - is it ?

Google hits

4-20mA 1,040,000
4-19mA 138

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist