The Orion AQ4500 offers a dual-source LED which allows readings that comply with both EPA 180.1 and ISO 7027. In the range of 0 to 40 NTU, the AQ4500 offers a ratiometric range which will give EPA, GLI method 2 equivalent numbers.

This portable field unit features an IP67, waterproof design with typical battery life of over 1000 hours on one set of batteries, and datalog capacity of 100 points which can later be downloaded to a printer or computer.