Challenge
Create a low-cost, handheld battery powered fluorometer for use in laboratory settings to measure trace chemicals in industrial reverse osmosis treatment systems.
Solution
A custom designed pen fluorometer with a membrane keypad and LCD display, based on the Texas Instruments MSP430F427 16‑bit ultra-low-power microcontroller.
Summary
Industrial reverse osmosis (RO) water treatment is used to purify process water by removing impurities. As pressurized raw water enters the RO system, a small amount of pure water passes through a filter membrane. /portable_chemical_analyzer.jpg)
The balance of the water moves alongside the membrane without being filtered and is returned to storage tanks. Water pH and chemical balance is important to prevent scale, corrosion, and biological growth within the closed loop system. Chemicals are added to the water to prevent these damaging conditions. It is important to monitor chemical concentrations to ensure no over- or under-dosing occurs and to protect the environment as feedwater becomes depleted and exchanged with fresh sources.
A leading water treatment company approached Tecnova to design and manufacture a device to measure water chemical treatment concentrations. Existing devices were large, expensive, and not portable for field use. A battery powered portable device was needed to allow field laboratories to determine the correct dosage of chemicals required for the RO process to run at full capacity.
Tecnova designed a custom enclosure containing a water channel, electronics, LEDs, optical filters, and photo diodes. The handheld design includes an LCD to display measurement data, a three-button membrane keypad to take measurements and perform calibration, and on-board storage of calibration values within the microprocessor.
The result is a small battery powered pen fluorometer, based on the low power TI MSP430F427 microcontroller with an internal 16-bit analog-to-digital converter and direct LCD drive. High accuracy measurements of water chemicals are taken using LEDs, optical filters, and photo diodes as the process water passes through the water channel.
