ABB Process Photometers includes:
The PUV3402 and PIR3502 process photometers optical path consists of an IR or UV source, a brushless chopper motor, a multichannel filter wheel, lenses, cell with windows, and a solid state IR or UV detector.
The brushless chopper motor rotates the multichannel filter wheel reference and measure filters, alternately and continuously, into and out of the optical path. The lenses, L1 through L4, focus and collimate the source radiation
through the sample cell path to the detector.
On a multichannel photometer, a reference wavelength is chosen where the stream components have little or no absorbance. The measure wavelength or wavelengths are chosen where the measured components have absorbance. The microprocessor will then use matrix algebra and apply the proper response factor to each filter to eliminate interference’s on the desired component and convert the absorbance to a component concentration.
Advantages of the design
The PUV3402 and PIR3502 process photometers use a fixed
wavelength filter, single beam, multichannel principle. This
design concept offers several advantages:
- Produces a simple mechanical design that promotes easier service and maintenance.
- Compensates for obstruction of cell windows.
- Compensates for source and detector aging.
- Permits the sample cell to be isolated from the electronics.
- Enable multicomponent analysis.