HM Digital what isinstruments?

Where to buy testers HM Digital ?

Learn about the company HM Digital and its creation, HM Digital was created in 1987, HM Digital, Inc.(formerly known as Heemang Electronics) is a manufacturer of equipment to test your water and your nutrient solution now recognized worldwide for providing the best values, the most reliable in testing instrumentation, testing water and your nutrient solutions for hydroponics , especially theTDS meter , EC increasingly popular in the market for precision electronic instrumentation.

Products and testers HM Digital are designed in close partnership between our Los Angeles, California office and our ISO-9001 certified factory in Seoul, Korea, HM Digital produces high quality water testing and monitoring equipment for all types of water treatment and purification systems including reverse osmosis water such as GrowmaxWater orAquariopure RO systems.

HM Digital sells its products to over 50 countries worldwide. HM Digital alsooffers OEM services for customized products and private companies, if you want to do private labeling that is to say, a private label with your image.

in 2000, the U.S. office was established in Los Angeles, California, to provide and develop marketing, customer service and distribution for the Americas, Europe, Africa, Middle East, Australia and South Asia. We strive to always provide the best value and care to quickly serve our distributors and customers.

HM Digital culture Indoor has been selected as the exclusive and official distributor in France since 2010, if you are looking for a wholesaler, a distributor, a stockist, a store distributing HM Digital if you are looking for a wholesaler, a distributor, a stockist, a store distributing in France, contact or visit Culture Indoor, the leader in hydroponics and aeroponics.

Our Controllers HM Digital portable controllers such as TDS, EC, pH, ORP, in-line monitors, controllers and accessories for reverse osmosis water filters, water purification systems, hydroponics, aquariums, swimming pools and many other applications are superior in construction and performance, yet made available at a very economical cost. HM DigitaltDS, Inc. is the only manufacturer of cost-effective in-line TDS monitors that measure total dissolved solids (TDS) levels of feed and product lines at the same time, an effective way to compare rejection rates and calibrate the reverse osmosis membrane, water purification.

With the water test instruments HM Digitalyou will know if your water is pure.

Please click on the products HM Digital to find out more about which PH tester or EC is right for you.

What is a PH tester and what is electroconductivity and EC?

Discover the new product ! EC-3M Conductivity Tester

The EC-3M is a portableelectroconductivity tester that measures electrical conductivity with a range of 0-9.99 millisiemens (mS). It includes a built-in digital thermometer and easy-to-read LCD display and a convenient vinyl case with belt clip.

Discover calibration solutions: pH Storage & Buffer Solutions

Our pH Electrode Storage Solution is ideal for extending the life of the probe on your pH-200 and PH-80, while our individual pH Buffer Solutions provide a simple and convenient way to calibrate your meter(s) to pH 4.00 & PH 7.00.

TDS AND CONDUCTIVITY (EC)

What isEC?

Go to our pages on electro-conductivity.

What should be the EC level of my water?

There is no specific level or "right or wrong" answer to this question. Generally speaking, for drinking water, a lower EC level (purer water) is preferred. The U.S. EPA, all U.S. states, the World Health Organization (WHO), and most countries impose maximum limits on EC allowed in drinking water. These limits are typically 500 or 1000 ppm, but they vary. There is no known minimum for drinking water.

In addition to drinking water, a CE level is specific for each particular application and use. While humans generally prefer purer water for their health, fish and plants, for example, require water with a wide range of EC levels, most of which are higher than safe human drinking water. If you are using a meter to test the water for a particular device, object or operation, contact the manufacturer of that object. For example, if you are using the meter to test the effectiveness of a water filtration system, contact the manufacturer of that system for recommended EC levels. If you are testing water for a pool, plants, fish, etc. Contact a specialist for your specific application, additive or nutrient manufacturer.

How do I take care of my EC Tester?
Why do I get different readings in the same water with the same meter?

The reasons for the varying readings are as follows:

Ions	The nature of positively charged ions (which is what TDS meters measure) is that they are always in motion. Therefore, there can always be variances in conductivity, and therefore a different reading.
Temperature	Even with ATC, which means temperature compensation, temperature changes of a tenth of a degree can increase or decrease conductivity. In addition, the temperature coefficient (what the reading is multiplied by to adjust for temperature differences) varies slightly over the ppm range. Our meters and virtually all meters under 500€ have a single temperature coefficient, regardless of the range. The new COM-100 offers three temperature coefficient options, but each is linear when selected.
Air bubbles	Even a small air bubble that has adhered to one of the probes could potentially affect the conductivity, and therefore the reading.
Persistent electrical charges	Electrical charges from fingers, static electricity from clothing, etc. on the meter and persistent electrical charges in the water will affect the conductivity of the water.
Knife / cup material	Plastic cups retain persistent electrical charges more than glass. If the meter touches the side of the glass or plastic, it may pick up a slight charge. If the plastic holds a charge, it could also affect the water.
Volume Changes	The amount of water in the sample can affect the conductivity. Different volumes of the same water can have different conductivity levels. Displacement can also affect conductivity.
Probe Positioning	The depth and position of the probe in the water sample can also affect conductivity. For example, if a meter is immersed in water, removed and immersed in water again, but in a different location, the reading may change.

How can I get the best possible readings?

Shake it up	Always be sure to shake excess water out of the meter before dipping it into a water sample, even if it is the same water.
Shake / Tap	After dipping the meter in water, always tap lightly against the side and shake the meter to remove any lingering air bubbles or electrical charges.
Positioning	When taking the reading, always make sure to hold the meter upright without touching the sides or bottom of the glass/beaker/cup. The probes should be suspended as close to the center of the water sample as possible.
Time	The longer the meter is in the water, the more accurate the reading will be.
Temperature	25 degrees Celsius is the ideal temperature for conductivity readings, even if the meter has ATC.
Rinse	If you are switching from very low to very high water, always rinse the probes with distilled water to avoid buildup.

Can I use the cap as a receptacle for testing?

No. The cap is for storage and protection only. For best results, use a larger beaker, cup, glass, etc., so there is a larger volume of water to test. Also, to ensure a long life of your product, TDS / EC sensors should be stored dry.

Are TDS meters really conductivity meters?

Yes. While EC and TDS are often used synonymously, there are some important differences to note. EC, when applied to water, refers to the electrical charge of a given water sample. TDS refers to the total amount of substances in the water other than pure H2O. The only real way to measure TDS is to evaporate the water and weigh what is left. Since this is almost impossible for the average person to do, is it possible to estimate the TDS level by measuring the EC of the water. Every digital TDS meter in the world is in fact an EC meter.

All elements have a certain electrical charge. Therefore, it is possible to closely estimate the amount of TDS by determining the EC of the water. However, since different elements have different charges, it is necessary to convert the EC to TDS using a scale that mimics the charge of that type of water.

The most common water samples are as follows, and for the COM-100, each has its own conversion factor:

KCl	Potassium chloride is the international standard for calibrating instruments that measure conductivity. The COM-100 is factory calibrated with a 1413 microsiemens solution and the default mode is EC-KCl. The conversion factor for KCl is 0.5-0.57.
442 ^TM	Developed by Myron L Company, 442 ^TM simulates the properties of natural water (rivers, lakes, wells, drinking water, etc.) with a combination of 40% Sodium Bicarbonate, 40% Sodium Sulfate and 20% Chloride. The 442 conversion factor is 0.65 to 0.85.
NaCl	Sodium chloride is used in water where the predominant ions are NaCl or whose properties are similar to NaCl, such as sea water and brackish water. The conversion factor for NaCl is 0.47 to 0.5.

Measurements in EC (μS) do not have a conversion factor, but require the proper setting of the appropriate temperature coefficient.

Most HM digital TDS meters other than the COM-100 use the NaCl conversion factor (average 0.5). Some products are available with the 442 conversion factor.

Is exact precision always necessary when testing TDS or conductivity?

Usually not. TDS is mainly over the range. For the majority of industries that require TDS testing, such as drinking water, aquaculture, hydroponics, etc., it is more important for your TDS levels to be in a certain range. There are a few industries that require a specific ppm level, but that level is almost always zero. With the exception of colloidal silver, there is never a time when someone needs an absolute, precise TDS level in their water.

F.A.Q

What is the difference between a parameter and a scale?	A parameter is the measured characteristic. A scale is a particular range applied to the measurement of that parameter. For example, temperature is a parameter. Fahrenheit or Celsius is a scale.
Is"EC" a parameter or a scale?	"EC" is a parameter. It stands for electrical conductivity. There are a number of scales used in EC, most commonly micro-Siemens (μ S) or milli-Siemens (mS). For example, if a particular application calls for water with "2.0 EC", this is an incorrect determination. Most likely, the application calls for an EClevel of 2.0 mS. 2.0 mS = 2000 μ S.
What is that little μ symbol on my EC tester?	The symbol 'μ' is not a lowercase U, but the Greek letter Mu. It stands for micro, and when used with an S (μ S) it stands for mirco-Siemens, which is a scale used to measure EC.
How do I convert from EC (μ S) to TDS (ppm)?	The best thing to do is to use a TDS meter, which will automatically do the conversion. EC meters do not use conversion factors because there is no conversion. To convert to TDS, if you don't want to use a TDS meter, you will need to determine which conversion factor you want to use (NaCl, 442 or KCl) and do the calculations.
How can I use a TDS meter to test salt in salt generator pools?	All TDS meters from HM Digital tDS meters can be used to test salt (up to the maximum range of the meter). Salt is part of the total dissolved solids and therefore will be part or all of the reading. If you start by filtering the water, then adding salt, simply use the meter as you would under any circumstances. If there is only salt in the water, and the reading is 2500 ppm, then it is 2500 ppm (mg/L) of salt. If you start with tap water and fill a pool, for example, before adding salt, then first test the level of your tap water. Therefore, if your tap water is 200 ppm, and your pool needs to be 3500 ppm of salt, then add 3300 ppm of salt. (A small portion of the tap water TDS may be salt)
Can a TDS tester be used to test water softeners?	No. Water softeners do not retain TDS. Instead, water softeners work by an ion exchange process. As the water flows through the softener, it will pass through a resin, a bed of small plastic beads or a chemical matrix (called zeolite) that exchanges calcium and magnesium ions with sodium (salt) ions. Therefore, the TDS level will remain almost constant (there may be minor differences).
How do I convert from TDS(ppm) to EC(μS)?	The best thing to do is to use an EC meter. If you know the conversion factor used by your meter, you can do the calculations. Most HM digital meters use the conversion factor for NaCl, which is an average of 0.5. Therefore, if you are using a TDS meter with the NaCl conversion factor, multiply the reading by two, which will give you a close approximation of the EC level.
What is the EC-to-TDS conversion factor used by HM digital TDS meters?	Most HM digital TDS meters use the NaCl EC-to-TDS conversion factor , which is an average of 0.5. Some testers HM Digital testers , such as the COM-100 have selectable conversion factors, so you can choose the one you want to use. For specific meters, please contact HM Digital.
Don't you need minerals in your drinking water?	Inorganic minerals Mineral waters are believed to help provide elements for the body's metabolism. However, there is scientific evidence to suggest that most of these minerals are in inorganic (dead) form. While they can enter the circulation, they cannot be used in the physiological process of building the human cell. With this in mind, we can see that mineral water can give "dead" or "inorganic" minerals to the body that cannot be properly assimilated. These inorganic minerals only interfere with the delicate and complex biology of the body. The body's need for minerals is largely met by food, NOT DRINKING WATER. Fact Organic minerals in tap water account for only 1% of the total mineral content of water. A glass of orange juice contains more beneficial minerals than thirty gallons of untreated tap water. Organic or bioavailable minerals It is only after passing through the roots of plants that these inorganic minerals become organic (through photosynthesis) and able to be assimilated into our tissues in the form of Organic Minerals. Pure water eliminates inorganic mineral deposits in your body. Organic minerals are completely absorbed and remain in your tissues. According to many nutritionists, minerals are much easier to absorb when they come from food. Can you imagine going to your garden for a cup of dirt to eat instead of a nice carrot; or drinking a whole tub of water for less calcium than an 8-ounce glass of milk?
PH AND ORP How often should I calibrate a pH or ORP meter?	All pH and ORP meters should be calibrated frequently. For best results, HM Digital recommends calibrating the PH-200 and ORP-200 at least once a month. This may vary depending on the frequency and type of use. For example, if you test a wide range daily, for the most accurate measurements, you should calibrate your tester daily.
At what level should I calibrate my pH meter?	A pH meter should be calibrated as close as possible to the level that will be tested. The most common pH buffers are 4.0, 7.0 and 10.0. If you are testing a range, then you should calibrate in the middle of that range.
At what level should I calibrate my ORP meter?	An ORP meter should be calibrated as close as possible to the level that will be tested. However, a negative ORP buffer does not exist in nature. The reason is that the moment it is exposed to air, the milli-voltage will begin to change, affecting the reading. Therefore, an ORP meter can only be calibrated to a positive ORP level. If you are testing negative levels, calibrate to the lowest possible level. If you are testing a range, then you should calibrate in the middle of that range.
Should I expect accurate precision with my PH-200?	Yes, within the guaranteed accuracy stated, and if properly calibrated.
Should I expect accurate precision with my ORP-200?	In the positive range, yes, within the guaranteed accuracy stated, and if properly calibrated. In the negative range, obtaining spot accuracy is virtually impossible since the meter cannot be calibrated to a negative ORP buffer and also because a negative ORP will naturally change very quickly. Therefore, looking for a range of negative values will produce more effective test results.
Can I use the cap as a receptacle for testing?	No. The cap is for storage and protection only. For best results, use a larger beaker, cup, glass, etc., so there is a larger volume of water that will be tested. Also, in order to ensure a long life of your product, the pH/ORP sensors should be stored wet, in the appropriate electrode storage solution.
How can I get better negative measurements with my ORP-200?	Low oxygen (negative) water can be rich in minerals that can adhere to the platinum strip on the sensor. If you find that the ORP-200 is slow or insensitive to negative ORP water, you may need to clean the platinum strip.
How do I care for my PH-200 or ORP-200?	For best results, always ensure that the sensor is saturated in the storage solution (included in the cap and extra bottle). For best results, store meters upright to ensure complete saturation. Rinse the sensor in distilled water after each use, especially if you are testing water and liquids with high TDS content other than water. For best results, store meters upright to ensure complete saturation. Calibrate frequently.
ShouldpH and ORP sensors be stored in water?	Yes, the sensors should be stored in the appropriate storage solution. For best results, always make sure the sensor is saturated in the storage solution (included in the cap and extra bottle). For best results, store the meters upright to ensure complete saturation.
There is a white residue on my cap or sensor. Is this normal?	Yes. The white residue is the salt deposit from the storage solution, which is very high in salt concentration. Simply wipe the salt off with a tissue. Never touch the sensor glass with your fingers.
What should I do if I experience unusual readings?	For both PH-200 and ORP-200, it is because your meter probably needs to be calibrated, the sensor is dirty or the sensor is saturated in the storage solution. 1. Rinse the sensor in distilled water. 2. Store the sensor in the storage solution (with the meter upright). 3. Recalibrate your meter. 4. For the ORP-200, clean the platinum strip with a silver polishing strip.
Why doesn't the PH-200 or ORP-200 stabilize in distilled water?	The pH and ORP sensors react with conductivity. Therefore, they will not stabilize in distilled or pure water. If you must use the meters in distilled water, swirl the meter slightly in the water while waiting for the reading to stabilize. It will begin to stabilize after about 30 seconds.
My PH-200 is not calibrating. How do I fix this?	Sometimes, after use without regular calibration or in wide ranges, the PH-200 may miscalibrate to the wrong value. In this case, perform a "master reset". Instructions for the master reset can be found on page 5 of the user guide, marked as "For Advanced Users Only."
What should the pH or ORP level of the storage solution be?	You will not be able to get an accurate reading on the storage solution because it may not be enough, there is a sponge in the cap, and the value of the solution will quickly be corrupted by other liquids. You should not attempt to calibrate the storage solution. The only purpose of the storage solution is to keep the electrodes saturated. Always use a laboratory-certified pH or ORP buffer for calibration.