IQ Spectral Sensors to Measure Color Continuously
Color has always been an important parameter in water quality. To meet these market demands, WTW (a Xylem brand) introduces spectral UV-VIS color sensors for both sewage treatment plants and monitoring surface waters, including nitrate, carbons and total suspended solids.
WTW provides color sensors for continuous color measurement in acc. to APHA Hazen 2120 and DIN EN ISO 7887.
- Reliable and high accuracy by turbidity compensation
- All in one – Color, COD, NO3, TSS
- Robust materials such as Titanium and Peek
- Minimal maintenance effort by integrated ultrasonic cleaning
Methods
The WTW Spectral UV-VIS Color Sensors measure according to the method DIN EN ISO 7887:2011, method C and according to the method APHA 2120 2018 (Hazen), method C. In both cases, these are methods for measurement in the laboratory. In the case of DIN EN ISO 7887:2011, method C, the wavelength of 410 nm is specified. With APHA 2120 2018 (Hazen), method C, the wavelength is freely selectable. In this case, the sensors of the brand WTW offer the wavelengths 340, 350, 390, 445, 455 and 465 nm.
Measuring Principle
As with the laboratory methods mentioned above, the sensors determine the measured value with the help of an absorption measurement at the selected wavelength (e.g. 445 nm). The methods demand a filtration of the sample prior to the photometric determination. However, since this is not possible with continuous measurement using a sensor, the influence of the filter residue may have to be compensated in order to achieve better agreement with the laboratory measurement. This is done by means of turbidity compensation.
If turbidity compensation is activated, the absorption of the highest possible wavelength is subtracted from the absorption of the selected wavelength. The result is then converted into mg/l Pt/Co and given as True Color (TC).
If turbidity compensation is not activated, only the absorbance at the selected wavelength is used and converted to mg/l Pt/Co. This is the Apparent Color (AC).
UV-VIS Spectral Color Sensors
NiCaVis® 705 IQ SF Co
Spectral UV-VIS probe to measure Nitrate, Color, CODdiss., TOC, BOD, DOC, SAC and UVT254 in surface waters with integrated ultrasonic cleaning, multifunctional slide and shock-absorption-rings (order SACIQ separately)
CarboVis® 705 IQ TS Co
Spectral UV-VIS probe for measuring color, CODtot, CODdiss., TOC, BOD, DOC, SACtot., SACdiss., UVT254 and TSS in a WWTP drain/outlet with integrated ultrasonic cleaning, multifunctional slide and shock-absorption-rings (order SACIQ separately)
NiCaVis® 705 IQ TS Co
Spectral UV-VIS probe for measuring color, nitrate, CODtot, CODdiss., TOC, BOD, DOC, SACtot., SACdiss. and UVT254 in a WWTP drain/outlet with integrated ultrasonic cleaning, multifunctional slide and shock-absorption-rings (order SACIQ separately)
ColorVis 705 IQ
Spectral UV-VIS probe for measuring color (Hazen 340, 390, 445, 455, 465, ISO 410) with integrated ultrasonic cleaning, multifunctional slide and shock-absorption-rings (order SACIQ separately)
