Digital salinity meters

[-XENOMORPH-]

I have moved up from hydrometer to refractometer, now I'm thinking digital salinity meter. But prices seem to vary, 10 bux to 200. I only run a 55 gal fowlr. I don't spend the thousands sum of u might...lol.. What's a good , affordable one? Any recommendations? Thnx.

 

[Mikedawg]

Following along; would like something digital that doesn't require regular recalibration - if there is such equipment for less than $100. Kinda like the AquaMaxx "standard" refractometer for $60.

 

[Waters]

I have and like the Milwaukee....instructions says it requires frequent calibration but I haven't had to calibrate more than once every couple of weeks.

 

[Randy Holmes-Farley Verified Community Expert]

My preferred one is an old Orion model 128 conductivity probe (expensive; it could not be calibrated and never changed its readings in a standard), but I've also used the Pinpoint and found it easy and convenient to use. It didn't drift noticeably either. Don't leave them in salt water 24/7. Store them dry.

 

[chipmunkofdoom2]

I have the American Marine Pinpoint Salinity monitor. I absolutely love it. I like the concept of measuring salinity via conductivity rather than refractive index. Too many ways to skew the result with refractive index, in my opinion.

 

[jason2459]

I have the pinpoint salinity monitor (just over $100) and it is an economical salinity (conductivity) monitor that has better resolution and accuracy then most other devices we have at that price point of around $100. Though I do love my veegee refractometer the pinpoint is better though takes longer to come to a stable reading. Which is why I would choose to use my veegee over the pinpoint for normal measurements and has a resolution and accuracy of +/-1 is more then good enough for us.

Another digital read out option is the Milwaukee digital seawater refractometer (just over $100). Many like it. I'm not overly impressed with it. I do not like it can only calibrate to 0 with rodi/distilled water and wish it had a 2 point or option of where to calibrate calibration option. But it is easy to use and read. It's resolution is a salinity of 1 and accuracy +/-2.

A step up from there is the Misco digital seawater refractometer (~$400). It's more expensive and I don't personally think it's worth it for most hobbyist. But it is better then the Milwaukee and seems just as accurate and reliable as my veegee. I'm starting to reach for my Misco digital refractometer more and more over my veegee as I'm feeling more and more comfortable about it's reliability, accuracy, and precision. It has a resolution of 1 and accuracy of +/- 1 just like the veegee. Unfortunately, it can only be calibrated to 0 by the end user just like the Milwaukee. But the manufacturer does do a 2 point calibration before sending it out and can be provided with a NIST tracable certificate and at any point can be sent back to them, for a fee, have the same 2 point calibration done and cert. Useful for labs that require that. I also like it's smaller then the Milwaukee and has such a simple addition that I really like is an evaporation lid which I use just for the fact of blocking out light. On the Milwaukee I use my hand.

Then up from there would be higher end conductivity probes like the one Randy mentioned. Thomas Scientific Orion star is an "affordable" (~$1000) one that I would like to get and try out one day. Though again, I have to say for the normal hobbyist the veegee refractometer is what I would highly recommend. It is not digital but more then accurate enough and as long as you don't bang it around will hold it's calibration very very well. It also has one of the brightest viewers that I've experienced over many many many other refracometers.

For digital I would recommend the pin point salinity probe unless you want to spend the money on the Misco digital refractometer or even more on something like the Thomas scientific orion star conductivity meter.

 

[Steve McGlamery]

I have and like the Milwaukee....instructions says it requires frequent calibration but I haven't had to calibrate more than once every couple of weeks.

I have a Milwaukee and you calibrate it using steam distilled water, less than $1 gallon at Walmart. I calibrate every time I use the meter.

 

[Salty1962]

I have both a Milwaukee and a refractor. I have found the refractor to be quicker and easier to use. Any device, other than the expensive ones, are going to need calibration during use. I guess it's what you get used to using. JMO

 

[BCSreef]

I have a Milwaukee and you calibrate it using steam distilled water, less than $1 gallon at Walmart. I calibrate every time I use the meter.

I do almost the the same. Although, I don't think the Milwaukee can be calibrated. Technically, using distilled water is not a calibration, but a "zeroing". I also check a seawater standard every few weeks or so. My unit consistently reads 0.01 SG high on the standard. So a reading of 1.027 is actually 1.026.

You also need to be sure your sample temperature is at room temperature with Milwaukee to get the most accurate read.