Utility flow meters can last up to 20 years on a single battery, says Maxim Integrated. The company has announced the MAXREFDES70# ultrasonic flow meter reference which it claims can improve water and heat metering accuracy and operate for up to 20 years on a single A size battery.

The solid-state meter is 10 times more accurate that mechanical meters, says the company and four times more accurate than ultrasonic solutions, as well as reliable, with no wheels or moving parts.

Measuring as little as 0.5litres of water/minute with better than 1% accuracy, fast ultrasonic pulses can be customised to the pulse frequencies required by flow conditions. According to the company, it can detect even minor leaks that the mechanical meters will not find.

The design is based on the company’s MAX35101 time-to-digital converter with analogue front-end that measures the difference of upstream and downstream ultrasonic pulses. Supporting flow measurement at low rates (up to 30litre/hr), time-to-digital conversion accuracy of 20ps is claimed to be the highest available on the market today.

Free schematics, layout files, and firmware are available, as well as evaluation kit with the MAXREFDES70# board, transducers, and USB interface is available with evaluation software.

The MAXREFDES70# system includes a circuit board with the MAX35101, two RTD probes, and spool body. The schematics, layout files, and firmware are free and available for immediate use.