TECHNICAL DATA
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OPTISENS TSS 2000
www.krohne.com
07/2018 - 4006304401 - OPTISENS TSS 2000 en R01
7.1 Measuring principle
The measurement principle follows the transmitted light absorption principle with pulsed NIR
855 nm. In this case it utilises one emitter and one detector for absorption measurement of light
on suspended solids and particles. The light passes the measured particles between the emitter
and the detector. Depending on industry and application the absorption measurement principle
is used for the parameters extinction (optical density) or total suspended solids. Immersion
sensors are most often used to measure the absorption as Total Suspended Solids (TSS).
TSS is a key measurement for water, wastewater and certain industrial processes. Typically, TSS
is monitored through periodic grab samples and a filter test performed by a skilled technician.
TSS is the gravimetric dry-weight of particles trapped by a filter. TSS is typically expressed in
mg/l, g/l, and %. Total Suspended Solids (mg/l) = (filter weight after filtering
–
filter weight
before filtering) / sample volume in litres. Quantitative online TSS measurement is often done
with absorption sensors. The TSS sensors also provide immediate results for process control
and reduce the need for the time-consuming suspended solids lab analysis. Online sensors are
best used after calibration or correlation to the gravimetric TSS procedure.
The advantage of using NIR as light source is that this sensor is not affected by the colour of the
medium measured.
