Hach HQ40D Digital Multi Meter Kit for testing pH, Conductivity, TDS, Salinity, Dissolved Oxygen (DO), ORP and ISE | UK Stockist | The Laboratory Store
HQD Multi-parameter Meter - Can-Am Instruments
HQ40D Portable Dissolved Oxygen Meter, Premium Field Kit for Environmental Monitoring, with Field Luminescent DO Sensor, 5 m Cable | Hach USA - Overview - Obsolete
HQ40D Portable Multi Meter pH, Conductivity, Salinity, TDS, Dissolved Oxygen (DO), ORP and ISE For Water | Hach USA - Overview - Obsolete
HQ40D Portable pH Meter, Laboratory Kit for Water Quality, with Refill pH Electrode, 1 m Cable | Hach USA - Overview - Obsolete