We are pleased to announce the long-awaited publication of our article:
“Quantifying the Relation Between Electrical Conductivity and Salt Concentration for Dilution Gauging Via Dry Salt Injection”.
From the press release:
“This article provides new knowledge on the quantification of many salt dilution, stream gauging techniques. For those of you who have practiced salt dilution, this new knowledge will ultimately influence your standards of practice in the field! This article also contains documentation of the ‘distilled water correction technique’ for use in deriving a calibration factor.”
You can download the full article here.
We believe this is important work to support Salt Dilution measurements. It’s a big step towards reducing the need for in situ calibration. We worked hard to get the 0.486 mg·cm·μS-1·L-1 +/-2.8% in the abstract, which for me is the biggest take-away. The important caveat to this is you must have a properly calibrated meter using EU27888 (nlf) temperature compensation to 25°C.
Other takeaways are:
- Small dependence on EC.T (+1.5% increase over 0-500uS/cm), which works out to 0.000015 (mg·cm·μS-1·L-1 )/(uS/cm) or 0.0015 (mg·cm·μS-1·L-1 )/(100 uS/cm)
- Dilution Correction should be used if calibration standard uses distilled water. Two corrections are presented (post calibration correction is in the appendix)
- Various sensitivity tests such as:
- glass pipette vs autopipette (not significant)
- re-using standard solution for multiple calibrations vs. making new standard solution for each calibration (not significant)
- using distilled water standard (with correction) vs. using stream water as secondary solution (not significant)
- different probes (significant)
- temperature compensation (significant, try to be within a few degrees of insitu measurement temp)
- From the abstract: “The calibration factor can be determined with an uncertainty of less than ± 1% under “best-case” conditions, and the uncertainty may be as high as ± 4% under less favourable conditions. If calibration is not performed, CFT can be estimated from the relation
between CFT and background temperature-corrected electrical conductivity (ECBG) with an uncertainty of about ± 2% [for a particular site], or estimated as a set value of 0.486 mg·cm·μS-1·L-1 with an uncertainty of about ± 2.8% for a properly calibrated probe.”
CWRA-NASH Flow Regatta, Q Competition, and BBQ! Victoria, B.C. May 28, 2018
Don’t miss out on the upcoming CWRA-NASH Flow Regatta, Q Competition, and BBQ! coming May 28, 2018 during the Annual CWRA conference to be held in Victoria, B.C. Canada. You need not register for the full conference to participated in the Flow Regatta. A Flow Regatta is a great way to spend quality time with your colleagues, meet new people, learn new or improve on your existing methods, and test your mettle against the best hydrometric minds in the country. Fathom will be competing again this year, in addition to organizing. If you’d like to refresh your memory on the 2017 epic showdown, read our post here or the condensed CWRA article here. If you don’t believe me, Stu Hamilton provides corroboration in his post. Ours was modeled on the very successful NZHS event that Stu and I attended earlier in the year, written about here.
This year’s theme will be “Challenging Flow Measurement Conditions” and will again feature cutting edge commercial and pre-commercial technologies such as ADV, Salt Dilution, Structural Surface Image Velocimetry, and hopefully others. Let us know if you have an idea!
No, it’s not a typo, it’s a movement. We’ve proposed and had accepted a similar event at the European Geoscientist’s Union AGM. We just have to plan it now. April is just around the corner, really. So if you’d like to come, better get your funding sorted out asap.
Peyto Glacier Site visit with University of Saskatchewan
Center for Hydrology staff for the
Global Water Futures and Global Water Security Initiative
Pheuph, that’s a mouthful, but nobody can deny importance of water. So we hiked up to the Peyto Glacier near Canmore, AB to do some studying of very old water. As part of a joint initiative between Fathom Scientific Ltd. and the Centre for Hydrology in Canmore, we performed a reconnaissance of the site for an AutoSalt installation. There was no snow around, just very old water. The glacier was like a giant mythological beast slowly retreating to its mountain lair over centuries. It has behaviour over time scales we’re not used to. It shifts, and creeps, and its skin blisters and cracks and heals. I was reminded of hummingbirds and how quickly they move compared to human time scale. If you were to play a stop motion of a glacier over centuries, the humans would be buzzing around, building fires, building cities, warring, peacing, shooting stuff up to the moon, to the other planets, growing the electric grid, surfing, loving, watching tv, eating, watching soccer matches, and all the while the glaciers are slowly growing and retreating. I’m sure it means something, but I’m not sure what exactly.
Ye Ol’ Product Shop and Site updates
We’ve overhauled the website in all our spare time. You can now purchase Fathom products online. The elves that run the internet, plugging and unplugging cables and doing calculus on abacuses, will get right to work finding the product in our vast warehouses, packaging, and adding special gifts and goodwill in every order. Expect to be pleasantly surprised. In fact, best to wear a raincoat when you open your package. Oh look! T-HRECS and AutoSalt are On Sale! Get them while they’re hot! Limited supply! Act Now!
And while you’re browsing the site, check out the awesome photos on the home page, all Fathom Study Sites. And witness the testimonials at the bottom of the home page, all authentic and un-coerced statements. And wait, what! What is WIT? Read about this exciting beta version product here! Be one of the first kids on your block to show off this revolutionary new product/service. We guarantee you’ll be surprised.
And lastly, come visit us in Portland, Oregon at the AWRA Annual Conference. We’ll be presenting Advances in Automated Flow Monitoring using Tracer Methods on Thursday, Nov 9, 2017 from 3:30-5:00. Join us for afterwards for an epic hydrologist brewhouse pub crawl and networking event. It’ll be the best event you never remember.