The Captive Purity Refractometer is an incredibly accurate and easy to use device that eliminates the confusion associated with inexpensive hydrometers. Just place a couple of drops of water on the prism and hold to the light. Reads in percent and specific gravity. An absolute must for the serious marine hobbyist.
The Captive Purity Refractometer is an optical device (no batteries) dual scaled 0-100% specific gravity: 1.0 to 1.070. Calibrate with distilled water. Adjustable eyepiece, carrying case, pipette included. This model is ATC (automatic temperature compensating).
This Captive Purity Refractometer has additional features including:
- No Screwdriver Needed for Calibration
- Heavy Duty Hinge Pin Design
Main Features
Specifications
- No Screwdriver Needed for Calibration
- Heavy Duty Hinge Pin Design
What's in the Box
Manufacturer Info
Captive Purity manufactures water filtration and water testing supplies for marine and reef aquaria. The brand is best known for their high-quality line of reverse osmosis filter systems and accessories. Captive Purity also produces refractometers for testing salinity, portable pen-sized meters for testing pH as well as replacement filter media for their RO and RO/DI filter systems.
Warranty
30 day warranty
|
Articles
Expert Reviews
Blogs
|
Captive Purity Refractometer with Calibration Dial
Reviews
Refract
by
BRIAN WAGGLE
Excellent!
Posted: 3/25/2013 from ZANESVILLE, OH UNITED STATES
4.5
5
Experience Level:
Beginner
Comments:
Great product. It's my first refractometer, and the light makes it really easy to read.
Did you find this review helpful?
Yes
No
Poor Quality
by
KENNETH M FAGIN
Unsatisfactory
Posted: 9/6/2012 from Gaithersburg, MD UNITED STATES
0.5
5
Experience Level:
Expert
Comments:
I just got this. My old refractometer was much, much more solidly built (and cost more, $159, about ten or twelve years ago when I got it) but eventually got corroded out of useability due to saltwater drips over the years.I bought the one with the built-in light. That is where the primary defect lies. There is a barrel assembly above the prism that houses three button-cell batteries and a small LED peeking out over the prism. The LED will not stay lit. There seems to be a "sweet spot" where, when the cap to close the battery compartment and a collar around the push-button switch on the opposite end are arranged "just so," the light will come on when you push the switch. But then as soon as you push the switch to turn off the light, things seem to get misaligned again and light won't come back on. Maybe that is a "one-off" problem, but construction just feels "cheap," which may be cause of the problem.Also, the way the prism cover plate is connected to the end of the unit is odd. It uses a pin-in-slot arrangement (i.e., a lost-motion sort of connection) insteat of a pin-in-hole pivot arrangement, with two "ears" or "tabs" hanging down at a right angle to the cover plate and the mounting slots being located in those "ears." If the plate isn't moved so that the pins are located clearly at the ends of the slots before trying to close the cover, it would be very easy to break off the tabs or ears.Bottom line: I'm calling customer service next to get RMA to send this back for other refractometer.
Did you find this review helpful?
Yes
No
Great Product!
by
DOELL MESEY
Excellent!
Posted: 8/14/2012 from LOMA LINDA, CA UNITED STATES
5.0
5
Experience Level:
Intermediate
Comments:
Great product, easy to use and operate. I bought this because I have a 5 gallon nano aquarium(and a 75 gallon)and checking the salinity with a traditional swing arm Hydrometer was a ROYAL PAIN! Plus I didn't really trust the readings I was getting in the Hydrometer because you never know if you have all of the bubbles out. I love having the lighted version of this refractometer. I use reading glasses so I would imagine that if I had gotten the one without the light it would have been much harder to read. That being said, it is still a little difficult to count the exact lines (for salinity) but I can easily get a good idea of my salinity within a couple of seconds. My only bit of advice is before each use, wipe the glass and the cover with a lint-free cloth and after each use, wipe the glass and the cover with a paper towel first and then with a soft lint free cloth after. If there is any residue on the glass or the cover the reading will be off, even with RO or Distilled water.So don't keep recalibrating it, just make sure the surface is clean and lint free. All-in-all, this product works great and has saved me many headaches!
1 of 1 People found this review helpful, did you?
Yes
No
Unreliable
by
HSING YU LIANG
Unsatisfactory
Posted: 3/3/2012 from DIAMOND, CA UNITED STATES
0.5
5
Experience Level:
Expert
Comments:
Very unreliable, I have had to calibrate it every time when I use it. >"<
0 of 2 People found this review helpful, did you?
Yes
No
Does a Great Job!!!
by
RAY H
Great
Posted: 1/30/2012 from AURORA, CO UNITED STATES
4.0
5
Experience Level:
Expert
Comments:
This refractometer is very accurate and works great but the light is not very bright and is only really useful if you’re trying to read it in the dark. I would say it's a nice feature to have if you've got the money but not really worth the extra cost for a tighter budget.
Did you find this review helpful?
Yes
No
An excellent device
by
QUANG HUYNH
Excellent!
Posted: 1/18/2012 from FAIRFAX, VA UNITED STATES
5.0
5
Experience Level:
Beginner
Comments:
It's a well built instrument that you need to have for all marine aquarists. It's easy to use. Very important that it is stored at the same temperature and the temperature of the room when you do the initial calibration has to be the same with the temperature when you do your measurement. My Instant Ocean Hydrometer gives the same reading as this device. I however prefer the refractometer since you don't have worry about the bubbles that stick to the lever, filling the hydrometer with tank water and cleaning it after use each time to prevent minerals from being deposited on the lever which will eventually give you false readings. The cost of the refractometer is really affordable compared to other things you have already spent on this hobby.
Did you find this review helpful?
Yes
No
Great refractometer
by
MARCUS NEUMANN
Excellent!
Posted: 1/7/2012 from CYPRESS, CA UNITED STATES
5.0
5
Experience Level:
Intermediate
Comments:
Great tool and is a must have. The light works great. Very accurate and easy to use. Thanks Marine Depot!
Did you find this review helpful?
Yes
No
Very Satisfied
by
JEFFREY OLIPHANT
Excellent!
Posted: 12/1/2011 from PHOENIX, AZ UNITED STATES
5.0
5
Experience Level:
Intermediate
Comments:
I highly recommend this device. I'm very happy I purchased the lighted model. It has a focus on the view lense and stores nicely in the case provided. Very satisifed with my purchase.
Did you find this review helpful?
Yes
No
Excellent!
by
LEONARD THOME
Excellent!
Posted: 11/26/2011 from PORT NECHES, TX UNITED STATES
5.0
5
Experience Level:
Intermediate
Comments:
This device works flawlessly. Easy to calibrate and the added light makes viewing the results easy and without effort. I had one before that did not have a light and I must say that having a built in light makes all the difference. This is the refractometer to have, in my opinion.
Did you find this review helpful?
Yes
No
Excellent tool
by
CHRIS YOUNG
Excellent!
Posted: 11/17/2011 from BLAWNOX, PA UNITED STATES
5.0
5
Experience Level:
Intermediate
Comments:
I don't know how I lived without a refractometer before. This item is well made and very accurate! Gone are the days of a swing-arm hydrometer. This is well worth the $$ and pays for itself in spades.
Did you find this review helpful?
Yes
No