Abstract: A monitoring system for monitoring a parameter of a fluid stream. The system includes a sample cell with inlet and outlet ports for fluid, a light source, detector, fiber optic cables for transmitting light to the sample cell and transmitting a signal back to the detector. The baseline variability of parameter measurements are calculated.

Abstract: Stabilized formazin compositions suitable as turbidity standards. The compositions can be prepared by diluting a concentrated formazin composition with a diluent containing hexamethylenetetramine and, optionally, a water-soluble sulfate salt such as sodium sulfate. The pH of the stabilized compositions is in the range of about 7 to 11.

Abstract: A method is described for rapid, simple and economical verification of the accuracy of the determination of an on-line particle counter without disconnecting it from a stream of liquid being tested. The method involves injecting a known volume of a liquid containing a known number and size of particles into the stream of liquid upstream from the detector. The number of particles displayed prior to injection of the known volume of liquid is compared with (1) the number of particles displayed after injection, and (2) the known number of particles which have been injected. No other modifications of the equipment is required, and only low volumes of test standard are used.