[neilh20]

I know my local Sonoma State University is against devices connecting to the network. They even gone as far as removing all  ethernet sockets. As part of the local engineering capstone project using LoRa the students went off campus for testing, as the LoRa gateway needed to connect to a WiFi network

The simple answer for WiFi is what Sara described.

Because of the wider security concerns for IP based systems, there is a whole lot of technical initiatives  to manage admittance to larger local networks – so security is likely to get more proscribed.

Just an FYI, even if you got WiFi connecting, I’m still having reliability issues with the Modular Sensors S6B WiFi interface. https://github.com/EnviroDIY/ModularSensors/issues/347

 

[neilh20]

In case its of interest, I have a method of writing to the onboard EEPROM, and use it to track the revision of the board in the data file .csv on the uSD.      https://github.com/neilh10/ModularSensors/wiki/Hw-Mayfly-config-EEPROM

[neilh20]

Many thanks for the heads up on provisional dates. It helps with planning.

Its painful dealing with components that have become unavailable and locate comparables – I had to do that with the Modbus board.

[neilh20]

https://www.digi.com/products/models/xb3-c-a2-ut-001   says only 19 available at https://www.sapply.com

I just received  three from Arrow.com and they don’t have anymore stock.

[neilh20]

Hi @dan-wachusett – I’d be interested to hear how your measurements work out.

This is what I did for acceptance testing (and characterizing) on a number of different types of depth sensors for a 2013 project – https://www.envirodiy.org/measuring-low-water-in-streams-accurately/

The update since then is the hydrologists I work with use the LT-500 for reliability and accuracy, and also been moving over from the Onset U30 to using the Mayfly.

I wonder, has anybody received a specification for the Hydros-21 Gen 2? .

Typically I find that manufactures create internal releases (generation 2?) as an internal cost reduction, with the same specification. Though every manufacturer is unique, so wondering what Metergroup changes might be :)).    Insitu and Keller (and others)  have different lines of depth sensors for different measurement accuracy and methods.  The challenge for any manufacturer is the basic pressure sensor is similar – a pressure dependent resistor – piezo resistor. Temperature dependency of resistors is well studied, but challenging to work with when bumping up against a specific resistor technology’s limits – so different manufactures have different signal processing and manufacturing calibration for better linearity of the pressure sensor.

 

[neilh20]

faaaaantastic  !!!

My data looks good from the May 12.    Thankyou so much to everybody who has pulled that together.

[neilh20]

Hello Anthony, yes thanks for the clarification.

As an engineer, I am often asked is the solution more painful than the problem it is solving!

The problem breakdown, when looking through the eyes of hydrologists  ; a) is the remote sensors working?, b) is the delivered data to the web reliable? either visually or downloaded  c) how to back-up all the costly data collected to a safe repository for a complete history. (TNC sensibly does this for its data collected)

In terms of the current situation with the “corrupted catalog crosswalk”,

when its working (a) it is possible to see that the remote sensor is working, and the date under the sparkline plots appears accurately to represent the latest record deposited.

(b) for me when the data is delivered it is reliable, though could be incomplete. I use the sample_number, and plot it to quickly visualize any data loss.

(c) for the backup it can be obtained through local Mayfly uSD via boot net.  To be able to download a coherent  .csv  is definitely an advantage and is definitely valuable to be able to scrape it through an automated mechanism.   I’ve found the  wofpy interface complicated and has its own problems for the same type of variable.

Appreciate the work that is going on to fix it.

 

[neilh20]

Hi James, as I understand it you are right – its difficult to get an accurate rating curve under such conditions. That is the geology.  That is why there are hydrologists, and it takes having someone with experience to find  if there is a geological place  where a rating curve can be built.    regards

[neilh20]

Hi Shannon, do you know if they are using temperature compensation for the sensor on the Generation2. ? thanks

[neilh20]

Hi James, yes there is the challenge.     My take way from the report was that providing its exceeding 1cfs or 0.028m3/sec it can be done fairly accurately with traditionally USGS methods – which sounds like you are well in that range.  For environmentally significant flows in drought California we are often looking at less than 1cfs/0.028m3/sec

The CTD-12 scale is  0 to 10,000mm with 0.5% accuracy across depth range,   with the specification stating “no sharp changes in temperatures”. Resolution is different than accuracy.  Specifically they are saying no temperature compensation.   So the type of raw sensor (typically piezo electric, resistive) and how it responds to temperature change is critical – I’ve put out a lot of data on instruments I’ve used on how the apparent reported water depth changes with temperature. In some cases with lower cost instruments a small temperature change causes the reading to wildly swing across the range. So for the CTD-12 the range is +50mm to -50mm.     So if you can find a measurement situation where which has pretty stable temperature change  in water temperature (ice melt?) and can calibrate your CTD-12 across that temperature change,  its likely to be provide useful readings.  The places that have stable temperature’s are typically in ground water, if pumping they are also likely to have a large range of water movement – ideal perhaps for the CTD-12.  When I checked with the manufactures over a year ago they where thinking about doing temperature compensation, but no statements yet on that.

So then I would think you are looking for the water column depth to vary significantly over the range of your instrument.   Or for locations you have, what is the range of depth change for the flows. Can you place a sensor on the upstream side of the culvert

For environmental flows the hydrologists I’m working find that the Insitu LT500 is their instrument of choice with a 0.1% total accuracy (including temperature compensation) over 0-3m. It is however a top-end instrument when it comes to the sensor, the cable, and the stripped cable to be able to feed it in to a Mayfly modbus.

I’m personally trying to do more calibration an trialing with the Keller Nanolevel which is 0-3m and is a large capacitive based sensor.  However the first Mayfly I deployed with it, got stolen after 9mnths, fortunately the sensor cable pulled away so still have the sensor.  I’m looking to connect it over WiFi, so still working on that.

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