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D-D True Seawater Refractometer - #myaquariumshops#

D-D True Seawater Refractometer

2 sold in last 8 hours
DD H2ocean
3 In stock
Animals & Pet Supplies
RM250.00 MYR RM225.00 MYR
D-D True Seawater Refractometer Hand held instrument for the measurement of the TRUE Salinity and Specific Gravity (S.G.) of sea water by refractive index. What is different about the D-D Seawater Refractometer? Almost all hand held salt water refractometers available to the hobby are designed and calibrated for the testing...
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Description

D-D True Seawater Refractometer

Hand held instrument for the measurement of the TRUE Salinity and Specific Gravity (S.G.) of sea water by refractive index.

What is different about the D-D Seawater Refractometer?

Almost all hand held salt water refractometers available to the hobby are designed and calibrated for the testing of brine solutions, i.e. sodium chloride, and are not calibrated for the refractive index of natural sea water.

Even though the largest percentage of salt in the sea is sodium chloride, the presence of other significant ions such as magnesium and calcium in natural sea water results in a different refractive index relative to that of brine. A standard salt (brine) refractometer will therefore not give the correct salinity for natural sea water (NSW) and a conversion factor must be applied.

For example a 35ppt solution of NSW has the same refractive index as a 36.5ppt solution of brine.

After extensive development, D-D’s new ATC refractometer addresses this issue as the scale is calibrated for seawater giving true salinity results for aquarium use when correctly calibrated and greater accuracy than previously attainable.

Our refractometers feature a copper internal body which conducts heat faster than cheaper aluminium and plastic versions for faster and more accurate auto temperature compensation.

Product Code AQPR001

Easier to Read & ATC

Easier to Read

One of the other problems with most refractometers is that the scale displayed normally reads from 0-100ppt when we are really only interested in the region from 30-40ppt. Our new Seawater Refractometer has therefore been specifically designed to read from 0-40ppt which gives you 2.5 times the resolution of a normal 0-100 scale.

Auto Temperature Compensation (ATC)

There is a lot of misunderstanding concerning the way the ATC feature works and its effect on the refractometer at different ambient room temperatures.

Salinity is a measurement of a mass of salt in a mass of water and therefore does not vary with temperature however a refractometer does not measure salinity directly but measures the refractive index which is then displayed as salinity. The refractive index of a solution does vary with temperature therefore the reading that you measure with a refractometer is always temperature dependant.

An ATC refractometer has a bimetal strip inside the instrument that moves the reading scale as the temperature changes to compensate for the change in refractive index. What people do not generally understand is that it is the temperature of the instrument and not the water temperature that is important as the small sample of water used for testing will equilibrate within seconds to the temperature of the refractometer.

Once correctly calibrated at the set calibration temperature of 20oC the refractometer can then be used in environments where the ambient temperature and therefore instrument temperature would heat up or cool down within the range of the ATC which is between 10 and 30 centigrade.

Calibration

If you look at the scale above you will see that the refractometer states that it is calibrated at and displays the SG of seawater at 20C.

Most salt refractometers use this temperature and will be marked 20C or 20/20. Calibration should always be carried out with the instrument at 20C which is close to the average room temperature in most cases. Allow the refractometer to stand at this temperature for 30 minutes to equilibrate.

The D-D refractometer is designed with a copper body which is more expensive to manufacture but responds faster to ambient temperature changes than other materials.

Note that the refractive index is also dependant on the wavelength of light too and therefore a light source closest to daylight should also be used.

D-D refractometers are calibrated at 20C and so the calculated specific gravity at 35ppt displays a reading of 1.0266. This is the equivalent to a specific gravity reading of 1.0264 for a water sample temperature of 25C using a standard hydrometer that has a calibration temperature of 77F or 25C.

More reading ; Further reading - Salinity and its measurement article

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Shipping & Returns

Thanks you for supporting us. Presently all products sold on MyAquariumShops.com will be arranged and shipped out as soon as possible upon receiving confirmation of orders.

All shipping of products sold on MyAquariumshops.com will be shipped either the following method ;

1) Local shipment within Malaysia – West Malaysia

Next day delivery Door to Door courier with major courier company in Malaysia once notification of the parcel has been send. Customer will be provided with the information of the courier company together with a parcel tracking number via an email which they are registered with to enable them to track their parcel via their email and via SMS text message send to their registered phone no. However, due to some circumstances  there might be chances that the courier company might take longer than usual to make their delivery. Customers will be advised of the contact info for them to contact the courier company to check on their delivery status.

The main courier company which we use is Airpak Express, however at time due to certain circumstances, we may use other courier company for example, poslaju, GDEX, ect to send your parcel. 

2) Local shipment within Malaysia – East Malaysia / Singapore

Usually for East Malaysia ( Sabah , Sarawak ) and Singapore,  the parcel will take longer about Two to Three day for it to arrived. However subject to clearance , it might take a day or two more before the parcel reach your doorstep. Customers is advise to check with the courier company with the tracking number provided for exact detail.

3) Small parcel – local shipment within Malaysia

For smaller items, in order to helps our customer save on the shipping charges, we offer local registered article postage by Airpak Express . A tracking number will also be provided to the customer to enable them to track their own parcel. Customer will receive both an email notification as well as a SMS notification on their registered phone on once their order has been shipped.

4) International Shipment – Worldwide

We can ship internationally worldwide, however as we are unable to provide shipping fees online for all of our products, please contact us under the contact us page with the items you are interested in for the shipping price quote .

If any of the country is not included in the checking out, please send us an email with the items that you are interested in buying , and we will check and advise you on the shipping accordingly.

5) Free Shipping promotion

For West Malaysia delivery, we offer free shipping for orders amount rm 500 & above and for East Malaysia and Singapore customers, Order amount RM 1000 & above. For Bulky or heavy items, for example ,salts, rocks, sands and chiller above 9kg, it will be using PosLaju Sea shipment for postage to East malaysia. For sea shipment, the estimate arrival time is about 30 day.

From time to time, we might offer “FREE SHIPPING” to some of our products. Free shipping means that we will take care of all the shipping / delivery charges of the products to your door step. Prices reflected on the website is the final price that you have to pay without any additional shipping charges. Please subscribe toour Newsletter and follow us on our social media platform for latest promotion.

6) Free Shipping

We provide FREE SHIPPING for the following ;

West Malaysia ( Purchase over $ 500.00 )

East Malaysia ( Purchases over $ 1000.00 ) 

** For Bulk / Heavy items to East Malaysia it will be shipped out via POS LAJU SEA Shipment **

Singapore ( Purchases over $ 1000 ) 

7) Customer Pick up.

At the present moment, we only can handle customer pick up at Johor Bahru area only. For Johor Bahru customers , Please contact us after your order with your order no to arrange for self collect. Please select “ Local shipment pickup “ during check out of your purchases.

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