Eureka
Solinst Eureka EasyProbe
Cost-effective multiparameter water quality sonde in two versions: EasyProbe20 measures temperature, dissolved oxygen, conductivity and pH/ORP, and EasyProbe30 adds turbidity.

Part no.: TDG
Total dissolved gas (TDG) sensor that fits a Eureka multiprobe alongside other sensors, so no dedicated TDG instrument is needed.
Prices are given in the quote we send you.
TDG is the sum of the partial pressures of all gases dissolved in the water. Supersaturation, for instance from turbulent water, can cause gas bubble disease in fish, and sudden changes can damage gills and swim bladders.
The sensor is a pressure transducer with a gas pocket behind a gas-permeable membrane. It is factory calibrated and only occasionally needs re-zeroing to barometric pressure. The membrane absorbs water over time, which slows response, but the membrane tip is easy to replace.
Eureka is one of few makers whose TDG sensor goes into a multiprobe with DO, turbidity, pH and conductivity. It fits the Trimeter, Manta+30B, Manta+35 and Manta+40.
Source: the manufacturer's specification.
Eureka
Cost-effective multiparameter water quality sonde in two versions: EasyProbe20 measures temperature, dissolved oxygen, conductivity and pH/ORP, and EasyProbe30 adds turbidity.
Eureka
Part no.: Manta+20
Portable yet rugged multiprobe with temperature, pH, conductivity and optical DO, with ORP and depth as options. Fits in a backpack and suits spot checks and profiling.
Eureka
Part no.: Manta+30A
Multiprobe with wipered turbidity, temperature, pH, conductivity and optical DO. Light enough for spot checks and profiling, tough enough for extended deployments.