The McNab product line was one of the first practical industrial
across-the-pipe turbidity meters. The first units were shipped in the
early 1960's. These were absorption type meters with wavelengths from
visible to near infrared measuring turbidity, particles, concentration,
and color. These were relative instruments.
The original product was known as the Jacoby-Tarbox turbidity meter.
McNab purchased the product line in 1986. Its hallmarks were rugged
construction, sanitary design, calibration by optical filters, and the
ability to follow the "Lambert Beer Law" of optics.
In the 1970's the absorption system was enhanced with the
introduction of a 90º side scatter system. This had the benefits of
automatic self zeroing, color hue compensation, and high sensitivity.
Since that time McNab has developed and introduced digital analyzers
to monitor forward scatter (Model
RS), back scatter (Model
HSD), ultraviolet absorption (Model UVII), fluorescence (Model HSF),
dual angle (Model
DSB), extended dual angle (Model DSC), near infrared (Model
KSA), tristimulus color (Model
KSA), color dual and triple beam (Model
HSA & Model
KSA), as well as a dual-angle laboratory analyzer (Model
McNab introduced laboratory calibration in true engineering units of
measure, allowing real measure of accuracy, not just the "relative
concentration units" (CU) or unlabelled scales that were the old
standard for the industry. This allows for true automation of the
customer's quality control.
McNab has introduced a ten-fold improvement to sensitivity, signal to
noise, glass fogging, range, and accuracy. This extended the usefulness
over the original equipment.
Maintenance time, both preventive and corrective, have been
drastically cut, decreasing the interval to 1/10th of that required on
the earlier units. Also included was the concept of
"pro-active" maintenance where the instrument itself would
call for preventive maintenance in large part avoiding an unjustified
costly fixed maintenance schedule.
McNab's design philosophy was to extend the interval of maintenance
and calibration so as to have an on-line availability of better than
We are pleased to be the technical leaders in this field of in-pipe
optical instruments. This point of view is well documented with actual
field data log experiences.