HM Digital DM-2 tds Inline-Dual TDS commercial measuring device for testing hydroponics, gardening, aquarium, reefs, pools, spas, water treatment, drinking water filter systems

Works as it should

If you are making RO water a TDS meter is essential. This well designed and efficient little dual sensor TDS meter will connect to the RO system at two points of your own choosing. The permeate output line is a given for one; I would suggest that the best place for the other is between the membrane output and the DI module. This will allow you to monitor the efficiency of the membrane over time.Connecting up is very easy, all the fittings are provided. Each sensor has two small probes. You must ensure that when you push the sensor into the T fitting the sensor is turned so that you can clearly see both of the probes like a pair of goal posts in the fitting as you peer through it. Any other orientation will cause inaccuracy.The always informative guys at BRStv on You Tube have reviewed this product, giving it a thumbs up. Interestingly they contacted HM who confirmed that the sensors are designed to measure TDS in-line only and not in free standing water samples where accuracy will be compromisedI can't speak about battery life at this point but it has auto-shutoff anyway. Accuracy is very good as checked against a Hanna Instruments lab quality EC Meter. Can't be recalibrated so as time goes on you might want to check it against another meter and work with any off-set.

Allows you to monitor input and output headless, though would be nice if both were displayed at the same time

Arrived safe and sound. Very easy to install. Would recommend this product to all.

I have this installed in my under-sink RO system with T-pieces to allow me to place the probes in the feed water, the just post-RO product, or the just post-remineralisation filter. I have one of these Ts blanked at any one time.The monitor appears accurate though my only other reference is a CaCO3 water hardness kit which doesn't give me TDS. In my area CaCO3 is the main contributor to hardness and this monitor will be used to monitor the health status of my RO membrane and my remineraisation filter.The probes and leads seem well made and the supplied T-pieces seem adequate (though I used others that seem better suited for the probe insertion side, I can use the supplied ones for other projects).The listings, even on the HM Digital site, seem rather ambiguous about the calibration capability on this monitor. Calibration on this monitor is electronic and is per line so it's a bit more likely that a single sensor that is drifting a bit can be corrected without dragging the other off.Happy with my purchase

Much more soild than some other TDS meters I've had for the RODI system of my marine tank. Seems to perform as expected in the short time I've had it

Perfect. Does just what I need it to do :)

This product arrived with a faulty probe. However the supplier couldn't have been more apologetic or helpful and two replacement probes were sent straight away. It is now working perfectly on my ro water system. Great customer service and good product.

Habe auch schon eines verschenkt.Super Tool!

Si dovrebbe istallare con ogni sistema.Questo strumento ti indica l’efficenza massima del sistema e quando sostituire la membrana.Non averlo e come guidare una macchina senza contachilometri.

es preciso y tiene un display de tamaño correcto

Facile d'utilisation et moitié moins cher que le même sous marque tunze

Robusto ben fatto ,fa il suo lavoro egregiamente,tarato dalla fabbrica. PS la batteria è già montata sul dispositivo!