Payment & Shipping Terms:
|Certificates:||CE And ROHS||Type:||Portable/handed|
|Warranty Tds Meter Tester:||3 Years||Resolution:||10ppm|
|Operating Temperature:||°C~50°C||Product Name:||Custom Logo Water Test Instrument Tds Meter Tds Monitor|
Type: TDS meter
Measuring range: 0-9990ppm
Accuracy: ± 2%
Batteries: 2x 1.5V LR44 button cells
Auto shut-off: 10 minutes
ATC(Automatic Temperature Compensation)
Dimensions: 5.9L× 1.1W ×0.6 Hinches
1 x Poit TDS Meter
2 x 1.5V LR44 button cells
1 x carrying case of TDS Meter
1 x User's manual of TDS Meter
ns one needs to take into account the tightly bound water molecules that get dragged along as well, so one cannot simply look at molecular weights or ionic radii. This drag due to the size of the hydrated ion is, for example, why lithium (Li+) is so much less conductive than sodium, which in turn is less conductive than potassium (K+).
"Can I Just Use a Multimeter to Measure Conductivity?"
No. Several factors make it impossible to accurately measure conductivity with a standard multimeter. The size and shape of the electrodes are significant, but more important is what happens at those electrodes. If a DC current is applied to seawater, numerous reactions take place when the ions hit the electrodes. Some ions will plate out on the electrodes, some may bubble off as gases, and the electrodes themselves may dissolve. These and other effects all serve to change the nature of the solution at the electrode, impacting the measured conductivity.
So how do conductivity probes get around this problem? They use an AC current rather than DC. Using fields that oscillate very rapidly, there is no overall movement of ions toward one electrode or the other. The ions move one way for a tiny fraction of a second, and then back the other direction for the second half of the cycle. Overall, the solution and electrodes stay unchanged and the conductivity is accurately measured. Modern conductivity meters use complex AC waveforms to minimize additional complications such as capacitance, which can interfere with simple conductivity measurements.
In practice, commercial conductivity probes have either two or four electrodes, with the four-electrode version being more resistant to fouling and other effects that can cause degradation of the measurement. The electrodes are made of nonreactive materials such as epoxy/graphite, glass/platinum or stainless steel. The choice depends primarily on the nature of the solution to be tested, but nearly any commercial unit will be suitable for tap water.
How a TDS Meter Works?
TDS meters are, in reality, conductivity meters. They work by applying a voltage between two or more electrodes. Positively charged ions (e.g., sodium, Na+; calcium, Ca++; magnesium, Mg++; hydrogen ion, H+; etc.) will move toward the negatively charged electrode, and negatively charged ions (e.g., chloride, Cl-; sulfate, SO4--; bicarbonate, HCO3-; etc.) will move toward the positively charged electrode (Figure 1). Because these ions are charged and moving, they constitute an electrical current. The meter then monitors how much current is passing between the electrodes as a gauge of how many ions are in solution.
What Does a TDS Meter Actually Detect?
Since TDS meters are often used to test water "purity," it is important to understand what they do not detect. As conductivity meters in disguise, TDS meters will only detect mobile charged ions. They will not detect any neutral (uncharged) compounds. Such compounds include sugar, alcohol, many organics (including many pesticides and their residues), and unionized forms of silica, ammonia, and carbon dioxide. These meters also do not detect macroscopic particulates, as those are too large to move in the electric fields applied. So if you see "rusty" looking water from iron oxide particulates, that won't be measured. Neither will anything else that makes the water look cloudy. Bacteria and viruses also won't be detected.
Consequently, the term "total dissolved solids" is really quite a misnomer. "Total charged ions" is likely a much better term for what it measures. Fortunately, a measurement of total charged ions is good enough for many aquarium purposes.
In addition to how many ions are present, the measured conductivity of a solution is also a function of what ions are actually present. Table 1 shows the relative conductivity that is provided when equal numbers of different ions are present in water. There are differences between the conductivity of the different ions, and this fact becomes important in the discussion of the units that are used for conductivity in subsequent sections.
Ions with higher charges tend to have higher conductivity because they not only carry more charge but they respond more strongly to an electric field. Good examples of this are sulfate (SO4--) and calcium (Ca++), which have higher conductivities than sodium (Na+) or chloride (Cl-). Another effect is that larger ions tend to have more "drag" as they move through the water, and thus have lower conductivity. In such comparisons one needs to take into account the tightly bound water molecules that get dragged along as well, so one cannot simply look at molecular weights or ionic radii. This drag due to the size of the hydrated ion is, for example, why lithium (Li+) is so much less conductive than sodium, which in turn is less conductive than potassium (K+).
1.Q: Why you choose us?
A:1. We are manufacturer tds meter for 8 years. The quality is very good while the price is lower.
2. We can customize according to your needs, with more direct communication and shorter delivery time.
2.Q:What's the delivery time?
A:Normally within 2 days when your quantity is no more than 1000 pieces.
3.Q:What is the MOQ if i need tds meter with my brand/Logo ?
4.Q:What is the warranty period on this item?
A:It has a 3 years warranty since the date of delivery.
5.Q:What if I need a Certificate of Calibration?
A:80% of our item have certification , Such as CE , ROHS , LFGB . But all certification is in favor of our factory name and model . If you need a certification by favor of your company name and model , Please contact with our sales and discuss the detail extra fees.
6.Q: Do you test all your goods before delivery?
A: Yes, we have 100% test before delivery.
Contact Person: Carey Gao