Conductivity Meters: pinpoint vs used lab grade units

[Randy Holmes-Farley]

That’s a good choice for a good price.
Set top dial sets the range. YOu want the range to be the lowest possible without exceeding the conductivity of that range (mine blinks when that is the case).

So for RO/DI, for example, rotate the top dial all the way clockwise to 199.1 uS/cm, and read values in uS/cm.

For tank water, it would be all the way counterclockwisde to 199.9 mS/cm since you want to read 53 mS/cm or so.

 

[Tim Olson]

I've just received the Orion Conductivity Meter Model 122 with probe 012210

I've scoured the internet on a user manual for this exact model.

I can find a description of the probe but not the meter.

It looks like this.

I put set the meter on 199.9 ms/cm and it read at 26.6 in my tank.

I'll need to mess around with it more. It also says low battery. So I'll have to change that as well.

I also did some searching for the specific model and couldn't find anything either. One possibility is to contact support at ThermoFisher ... https://www.thermofisher.com/us/en/home/technical-resources.html.

 

[Tim Olson]

Another update

So I pulled the transformer from pinpoint ph meter and plugged it into the Orion meter.

I know there may be some variation due to the current, but I'm sure the transformer is grounded so it held a constant reading.

Here are my results.

Right cup is my reef water

Left is RO from my faucet.

Looks like I need to boost my salinity up.


Phewwww

It sure looks like it's working good. Also, just curious if you use a converter to change to ppt or specific gravity. I've been using Hamzas Reef calculator ... https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php.

 

[Randy Holmes-Farley]

It sure looks like it's working good. Also, just curious if you use a converter to change to ppt or specific gravity. I've been using Hamzas Reef calculator ... https://www.hamzasreef.com/Contents/Calculators/SalinityConversion.php.

I just use the conductivity value for my own purposes, but if someone wanted a conversion, I'd either just do the math (conductivity and salinity are linearly related, so 52 mS/cm = 52/53 x 35 ppt =34.3 ppt; 52/52 x 0264 (from 1.02640 = sg of 1.0259) or I'd get it from a table like the ones I made here (Table 1):

http://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[bozo]

Just another update

I opened up the Accurasea calibration bottle and tossed the probe in.


It reads 52.5 mS/cm.

Just about right.

Ill use the math stated above to get my correct reading.

I also tossed the probe in the tank for giggles and it showed the same reading as when I had tank water in the cup from yesterdays reading.

Good to know my ATO is consistent lol.

It's good to know that this probe is still accurate after all these years.

 

[Tim Olson]

That's great news

 

[Randy Holmes-Farley]

Nice.

 

[bozo]

I'm really loving this salinity meter and probe.

I have much more confidence in my saltwater mixing routine now that I have a meter and knowing that the probe is spot on.

I'm not sure why people even go for these other monitors/meters such as Hanna, Milwaukee, ice cap if you can just browse eBay for a while until you snag one that is affordable for you. Shoot I'd even skip the refractor meter option as well.

I only searched for about 3 days. Prior to finding this thread I was lookin for a Hanna Meter for 3 weeks. So glad I found this. Life changer forsure.

Thanks again Tim and Randy.

 

[Randy Holmes-Farley]

I'm glad to hear its working out for you.

 

[Muffin87]

I actually have quit using my Pinpoint Salinity Monitor, since I just couldn't trust it to give me a consistent and accurate reading. I've had, and used, my Pinpoint Salinity Monitor for over 4 years and experienced a number of issues. Here are a few:

• Very sensitive to electric fields, so I couldn't use it in the sump or tank. I had to take a sample out and measure it on the table. This also required waiting about 4 minutes for the reading to somewhat stabilize.
• I never felt the temperature compensation really worked right. When I measured the sample on the table, it would start off as one reading, then continually change as the sample transitioned to room temperature. So, I found I didn't know when to stop and take down the reading.
• Has to be carefully calibrated with the right standard fluid ... Hint - It's not the Pinpoint standard. I found the AccuraSea standard to be the most accurate.
• The reading varied on battery strength. As the battery got low, the readings would change.

Here's a thread I started in February about "Why do my Salinity measurements vary by 0.002 sg between refractometer and conductivity testers?", which describes my quest to find the most accurate and consistent salinity device.

Overall, my conclusion was:
1. Use an accurate standard, which turned out to be AcuraSea, to calibrate to.
2. I found that 2 devices gave the most accurate and consistent results. VeeGee STX-3 refractomer was the best analog device and the Hanna Salinity Tester - HI 98319 to be the best digital one.

With regard to a "full-time" probe, I can't recommend anything. I've heard the Neptune probe is ok, if you have a Neptune. Although, I would only use it to capture salinity changes, not to give a accurate readings.

I hope this helps make you decision.

@Randy Holmes-Farley
Can you recommend some good conductivity meters that are available on the market, and not just as used?
The pinpoint doesn't seem suitable. With these shortcomings, one may just stick with a refractometer.

 

[Randy Holmes-Farley]

@Randy Holmes-Farley
Can you recommend some good conductivity meters that are available on the market, and not just as used?
The pinpoint doesn't seem suitable. With these shortcomings, one may just stick with a refractometer.

How much are you wanting to spend?

 

[Muffin87]

Well it should be available for purchase in Europe.
I'm looking for accurate measurements, and doesn't need to be calibrated more than once every 6 months or a year.
Anything that reliable in the 300- 400 dollars range?

I'm a bit tempted by this ebay listing. Just not sure what the chances are that the probe still works well.

Orion Conductivity Meter Model 122 LOWER KNOB HAS HAIRLINE CRACK | eBay

Condition is "Used".

www.ebay.com

How long would an Orion probe last?



This Orion Thermo Scientific™ Salt 6+ Handheld Meters

https://www.thermofisher.com/order/catalog/product/ECSALT603PLUSK

This one also looks good, but I'm unable to tell if I'd have to constantly calibrate it.
I'd like something that I can just trust without the doubt that it may have fallen out of calibration since I last calibrated it 2 months ago.

 

[bozo]

Just wanted to update that my orion salinity meter is still going strong.

highly recommend it

 

[Randy Holmes-Farley]

Just wanted to update that my orion salinity meter is still going strong.

highly recommend it

Glad to hear it!