AnyLeaf Water Monitor User manual

AnyLeaf Water Monitor User Manual August 2021
Overview
The Water Monitor is a sensor suite that measures 4 properties of water:
Temperature, pH, oxidation-reduction potentia (ORP), and e ectrica conductivity
(EC). The EC sensor may be used to estimate tota disso ved so ids (TDS). These
measurements can be used for a number of app ications. Some suggestions are
aboratory, hydroponics, aquariums, swimming poo s, and water-qua ity fie d
work. The Water Monitor can be powered using USB-C, or using 3 AA batteries.
Specifications
•Dimensions: 50 × 25 × 17(height) mm
•Weight: 52 grams (8oz)
•Safe temperature range: 0-80°C
•pH precision: 0.01, with a suitab e sensor
•pH Range: 0 - 14
•pH an ORP electro e esign: Doub e junction g ass e ectrode
•pH an ORP bulb shape: Spherica
•Temperature precision: 0.03°C
•Temperature accuracy: 0.5°C and better
•Compatible EC cell constants: K=0.01, K=0.1, K=1.0, K=10 cm ¹⁻
•Con uctivity range: 0.01 µS/cm to 1 S/cm
•Con uctivity range with K=1.0 probe: 100μS/cm to 10mS/cm
•Power: USB-C, or 3 × AA batteries (inc uded)
•Sensor interface: BNC Ma e (Accepts BNC fema e sensors) for pH, ORP,
and EC. 3-wire screw termina s for RTD.
•Power consumption (typical): 500μW
Quick start
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To get started, connect the three sensors that use cy indrica connectors (BNC) to
the Water Monitor. Left-to-right, with the screen facing you, and the ports at the
bottom: conductivity (b ack sensor), ORP (tea sensor), pH (c ear sensor). If not
a ready connected, connect the temperature sensor (A 3-wire resistance
temperature detector (RTD)) to screws on the eft side, using a Phi ips-head
screwdriver; the b ue termina is on the top.
Connect power by p ugging the Water Monitor into wa power, or a PC, using the
USB-C Port. Press the contro switch inwards to power on the device. You wi see
four readings. When taking measurements, unscrew the caps on the probes, and
p ace the probes into the water you’d ike to measure. If you don’t need a certain
measurement, you can eave that probe disconnected.
The Water Monitor can be powered over USB using its USB-C port, or using 3 AA
batteries, which are inc uded in the package. You may use rechargeab e batteries,
but the Water Monitor wi not charge them; you must charge separate y. The
Water Monitor wi operate for about 6 weeks on a sing e set of batteries.
Display
The Water Monitor uses a 4.2” e-paper disp ay. This a ows it to ho d an image on
the disp ay without using any power, providing a ong battery ife. As a
consequence of the way this disp ay operates, every few screen refreshes (eg
when a reading change, or you navigate in the menu), the screen wi f ash white-
b ack-white for 1-2 seconds. This is ca ed a full refresh, and is norma . The
readings may become b urry during refreshes where this doesn’t occur. Note that
a fu refresh wi occur once readings have stabi ized.
Interface
You can change settings on the Water Monitor using the 5-way contro switch,
ocated to the eft of its screen. From the home page, move the stick right to
enter the menu. In the menu, move the stick up or down to se ect different
items; the se ected item is indicated by a carat to its eft. Press forward to access
or togg e the item, and press back to go to the home page. Se ecting a unit to
change wi togg e that unit. Se ecting a ca ibration process wi enter that
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ca ibration; instructions on screen wi exp ain how to proceed. During a
ca ibration, press backwards to abort, and revert to the previous ca ibration.
Up ate interval
When p ugged in, readings wi update twice a second. To increase battery ife,
updates occur more s ow y when on battery power. The rate of these updates is
se ectab e using the Update setting in the menu. Here, you can togg e between 1
second, 5 seconds, 30 seconds, and 5 minutes. 5 seconds is the defau t interva .
The s ower the update interva , the onger the battery wi ast. With a 5-second
interva , batteries wi ast approximate y 2 months. Which setting you choose
depends on the use case. For examp e, for ong-term system hea th
measurement, you may wish to set a 5 minute interva to maximize battery ife.
Connecting to a PC
You can connect the Water Monitor to a PC or Raspberry Pi to send its readings
there, by p ugging it into the PC’s USB port. The easiest way to take advantage of
this is by using the Water Monitor view software, avai ab e at https://github.com/
any eaf/water-mon-app/re eases. Down oad the version suitab e for your
operating system. (Current y avai ab e for Windows and Linux), unzip, and run the
resu ting executab e. It wi then start a web server, and provide instructions on
how to view readings: By entering localhost in a browser’s URL bar on that
computer, or by entering that computer’s IP address, which it disp ays, on
another device on your network, such as a mobi e phone. This software is open
source: You’re encouraged to the view the source code, and modify if if you wish.
A Python ibrary that a ows access to the readings is a so avai ab e: pip install
anyleaf. This is the same ibrary used to access the standa one AnyLeaf modu es.
In addition to viewing readings using a web browser, you can access the readings
using the AnyLeaf Python ibrary: https://github.com/AnyLeaf/any eaf-python.
Reference the water_monitor.py examp e (examp es fo der) for the code used to
take readings.
You can use MyCodo to easi y integrate with other sensors, and disp ay and og
readings from a Raspberry Pi. You can down oad and earn about MyCodo here:
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https://kizniche.github.io/Mycodo/ Once set up, you can add the AnyLeaf
WaterMonitor as an input.
Up ate rate
When p ugged in, the Water Monitor refreshes readings every second. When on
battery power, the update interva is customizab e, by using the Update setting in
the menu. Setting a onger interva resu ts in improved battery ife, at the cost of
s ower updates. If you’re monitoring ong-term system hea th, a onger update
interva a ows you to go onger between battery changes. When p ugged in, the
user-customizab e setting is ignored.
Calibration
pH, ORP, and EC can be ca ibrated by se ecting their respective ca ibration items
in the menu. (Press forward on the contro switch, se ect the item you wish to
ca ibrate using up and down, then press forward to start). Each ca ibration screen
disp ays instructions on how to perform the ca ibration. Note that you need
ca ibration so utions (eg pH buffers, conductivity standards etc) to initiate
ca ibration. If you wish to revert to defau t ca ibration (and other defau t settings),
you can se ect Reset all from the menu.
pH ca ibration uses either 2 or 3 points: 2-point ca ibration mode s pH as a inear
re ationship with probe output vo tage – this is good enough for most uses. 3-
point ca ibration account for non inearity in readings – this is suitab e for scientific
measurements. You can read about how pH ca ibration works from our b og artic e
on the subject: https://www.any eaf.org/b og/how-to-ca ibrate-ph-sensors.
EC and ORP ca ibration is simp er, as they each use sing e-point ca ibration. They
both use a inear mode between the ca ibration point, and 0. ORP ca ibration
maps measured vo tage to ORP vo tage (They shou d be very simi ar), and EC
ca ibration compensates for imperfections in the probe and measuring setup.
pH and ORP probes need to be re-ca ibrated periodica y, as ion-se ective probes
ike this drift over time. More the purpose of hydroponics or aquarium monitoring,
you can ca ibrate once every few months. EC probes shou dn’t drift over time, and
you may be ab e to get away with never ca ibrating, or ca ibrating once for your
probe.
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Configuring con uctivity (EC) probe cell constant
The Water Monitor is avai ab e with a K=1.0 (cm-1) ce constant. It’s capab e of
working with other probes that p ug into BNC ports, inc uding ones with different
ce constants. This is usefu for reading conductivity at varying ranges. (See
specifications above). To change ce constant, adjust the EC setting in the menu
to togg e between K=0.01, K=0.1, K=1.0, and K=10.0. If this setting doesn’t
match your probe, EC readings wi be incorrect.
Estimating Total Dissolve Soli s (TDS)
By setting the EC unit to PPM mode (Press the switch forward to enter the menu;
down to se ect EC unit, forward to change the unit, then bac to get out of the
menu), tota disso ved so ids are approximated based on conductivity and
temperature readings. PPM is ca cu ated as 0.5 × conductivity reading in μS/cm.
It’s adjusted by 1.95% for each °C difference in temperature from a reference of
25°C. An increase in temperature causes a decrease in measured TDS – this is
because conductivity increases with temperature. So, to get an accurate estimate
of tota disso ved so ids, we compensate for this. Readings disp ayed in mS/cm or
μS/cm aren’t temperature-compensated: They’re direct conductivity readings.
Up ating firmware
The firmware running on the Water Monitor can be updated to add features,
improve performance, or fix bugs. Information on updates, and firmware
down oads are avai ab e on the AnyLeaf website: https://any eaf.org/ f irmware-
update. These updates are optiona , and descriptions of what they change are
shown with a down oad ink. To update, fo ow the instructions on that page.
When the updater asks to press the firmware update button, this is accessed
using a paper c ip or simi ar device, inserted through the sma ho e above the
contro switch.
Troubleshooting
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If you have any questions about or troub e with your Water Monitor, p ease emai
support at [email protected]
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