4. Troubleshooting

Last updated on 2022-12-02

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To access a printable PDF version of the EnviroDIY Troubleshooting Quick Guide please click the following link: EnviroDIY Monitoring Station Troubleshooting Quick Guide. The troubleshooting quick guide is designed to be printed to provide troubleshooting tips while in the field. Further explanations can be found in the text below.

4.1 Battery Dies

When battery level goes below ~3.7 V data transfer to the website and download to SD card will stop or be impaired.

1. Check solar panel and battery connection to the panel itself.
2. Ensure no corrosion has taken place.
3. No insect or rodents have chewed wires.
4. Check solar panel orientation, look at the live data, has it been charging or slowly dying-canopy cover can change and adjustments may need to be made.
5. Is the cell signal indicator light blinking at more than the given 4 second intervals? This may be an indication it is not finding a cell signal and draining your battery, reset power with reset button or turn ON/OFF.
6. For given light conditions you may need to upgrade to a larger battery or solar panel or both.

4.2 Data From the Real-Time Feed Stops

1. Cycle the power using either the reset button or turning switch ON/OFF.
   1. Check to see if the data are being recorded on the SD card. check the data card and see if data is being recorded every 5 minutes. When you turn the logger on (with a working battery), you’ll see the green light blink rapidly a couple times, then pause a second, then the red and green lights will blink back and forth 5 times really quickly (less than a second). Then everything will be dark, except for the yellow light which indicates the solar panel is charging the battery. If you stick around until the even 5 minute intervals (3:05, 3:10, 3:15, 3:20), you’ll see the green light turn on along with a red light in the far corner by the sensor jacks. After about 10 seconds, the sensor red light goes off, then you’ll see the small greenish/yellow light on the red cellular board start blinking every 2 seconds. It’ll do this for a little bit as it’s establishing a connection. Once it gets a valid cell connection, it blinks once every 4 seconds for about 10-15 seconds as it’s transmitting the data. Then the cell board light stops and the green light on the Mayfly goes out too, and the board is now asleep. If you aren’t seeing this sort of behavior on the 5-minute intervals, then something is wrong. But looking at the data on the card will also tell you if it’s logging properly and what the battery voltage is. There may be times where the battery is too low to power the cell board, but the Mayfly will still be recording data on the card, so that’s why we need to see what’s being recorded there.
   2. Loggers may “lock up” and stop connecting to the cellular network after a period where the cell network was unavailable or had extremely low signal strength. The only way to get them to “reconnect” is to just cycle the power on the logger.  Anytime you see a logger go offline and the battery voltage wasn’t too low (below 3.7 V)(Fig batt) the last time the network “heard” from the logger, then someone should just simply go to the station and cycle the power using the power switch on the Mayfly. There’s absolutely nothing wrong with cycling the power anytime the stations acts strange.  You should also swap out the memory card when you do this to see if the station has been recording data on the card during the cellular outage, or if for some reason the entire logger was paused.
   3. In cases where the station has marginal cell signal strength (and data transmission stops at times), after the signal is lost the cellular module doesn’t re-join the network properly, so someone has to go out and restart the station.  Should also look at the data card data to see what the battery voltage looks like for the times the logger is offline.
2. Battery has died (due to issues discussed above), replace battery, possibly with larger model.
3. Circuit board has for some reason shorted. Possible reasons for shorting:
   1. Cell module “antenna” has contacted the Mayfly board. This antenna is a small board with a wire attached to the cell Xbee board (red arrow in photo below). If the antenna comes in direct contact with the Mayfly board it will damage the board. The standard location for this antenna is outside the logger board case. If this antenna comes in direct contact with the Mayfly board it will most likely damage the board and a replacement will be required.
   2. Water has entered the logger box and contacted the Mayfly Data Logger board. Although the logger boxes are water tight there are ways in which water may enter including: bent hinges of the logger box door, defective logger box seals, debris (e.g.,grass, sticks) between the seals. If water does enter the box a dessicant pack can be used to dry it out, however, unless the source of water entry is dealt with it is likely that the Mayfly board will be damaged with repeated water exposure.
4. Cell signal may have been lost through a power outage, non-payment on your account, or cell tower issues. If you have ruled out power outage, contact your provider.
5. Hologram SIM card data plan has not been paid. If data stop on the same day of the month that the plan was last renewed this is likely the problem.  In this case money would just need to be added to the account, at which point data should begin transmitting again. Hologram will email a warning 24 hours prior to expiration.

4.3 Only One Sensor Shows Real-time Feed

1. Check wires from sensor to logger box, make sure it has not been severed.
2. Open case and check that the connection to the board is firm and that there is no corrosion.
3. Cycle power by using reset button or turning power switch ON/OFF.

4.4 Brown Varnish on Turbidity Sensor

Most of the metal sensors have this effect after a year or more. It’s a chemical reaction between the metal and some of the dissolved minerals in the water in this part of Pennsylvania. It shouldn’t affect the actual window of the sensor since it is optical epoxy and doesn’t attract the minerals like the metal does. We’ve had sensors out for multiple years and only used the stiff side of our general purpose cleaning brush to clear the window. If we have to clean a metal sensor, we’ve used a very weak oxalic acid rinse with gentle scrubbing, followed by a rinse with dilute hydrochloric acid to remove any traces of the oxalic. But again, it’s shouldn’t be necessary. If anyone wants to clean the actual optical window of the turbidity sensor, they should use care not to scratch the window or use a chemical that would interact with the epoxy because it will start to become opaque and that definitely will harm it.

4.5 Erratic Depth Measurements

From looking at the graph, it appears that the pressure part of the sensor is blown. You can see when it froze because the conductivity went to 0 overnight, meaning there was no liquid water around the sensor anymore, and then the next day the pressure shot up and said there was 3.5 meters of water. Ever since then, the pressure signal is a combination of depth plus water temperature, because when these sensors fail, the temperature-compensating part of the sensor gets magnified and you start seeing big “pressure” changes that exactly mirror the water temperature readings.

There’s no way to look at the sensor to assess the damage, so you’ll just have to remove it and replace it with a new one.  We’ve never had ice damage before, so we’re not sure if the company is going to replace this one (or three or four of the other DRWI sensors that froze recently). Since Merrill is so shallow, we don’t think it makes sense to put another new sensor in there until we’re sure all of the cold weather is done for the year, otherwise it’ll just break again the next time we get a good freeze.

4.6 Highly Variable Measurements

From time to time the CTD sensors arrive defective from the factory and show this type of noisiness. They will often get noisier over time, which is what looks like is happening there, therefore, a replacement sensor will probably be in order.

4.7 Spiky Conductivity Measurements

CTD sensor malfunction; replacement sensor needed

4.8 Rapid Change in Depth

A rock was lodged in the CTD sensor and pressing against the pressure transducer. That rock lodged in the sensor also somehow caused the conductivity to read abnormally low for some reason. After the rock was removed, conductivity was tested with three separate meters and each read about 1100 μS/cm. So all of the conductivity dated during the period with the inaccurate depth is probably false. This was a unique situation and is not observed regularly.