Measure. Analyze. Learn.
This is the Vernier Soil Moisture Sensor.
It's used to measure moisture content in soil.
So, you might use it in an agricultural setting,
that soil moisture would be important.
And so, you could actually monitor the soil under a plant,
see what happens there.
You might use it in bottle biology.
So, you've got one of your columns and you want to
monitor that soil moisture content.
So, that's what you use it for.
How it works: it actually measures the capacitance of the soil.
And, what happens is, is that the moisture content of the soil
changes the capacitance.
And so, it actually using, it's measuring the dielectric permittivity
of the soil, and it's proportional to, what happened, you know,
how much moisture there is.
And so, by changing the moisture in the section of the probe,
you're changing what the reading is.
Now, the reading on the sensor, is actually reading in
the volumetric water content of the soil.
And, it reads 0 to 45 percent.
Now, this causes issues sometimes.
You're like, "Why in the world would a soil that is really wet,
why does it read 45%?"
Well, the thing is, you have to think about, 'what is soil'?
Soil is made up by, you've got minerals, you've got some
organic content, and there's also spaces,
and so, you've got pore spaces in there.
It’s not a solid piece, and what happens is, is you add moisture
to the soil, you're filling up those pore spaces.
And, you can't have the soil be 100% water;
it's just not possible.
And so, that's why it reads in that realm.
So, it's a common unit that would be used in
measuring soil moisture content.
So, to use the sensor, we need to place it into the soil.
And, we use it by putting it in horizontally.
The, kind of, the natural inclination might be just to
take it and jam it into the soil.
You don't want to do that.
You want to have it go in sideways, this way.
Because, that way, you get a better reading.
And because, you're using, kind of, a slice
of the soil down below there.
And, it needs to go in that way.
So, let's go outside and I'll show you a real-world case of
how you would use this in the environment.
I'd like to show you, kind of, a common use case of this,
and how you would place it in the ground out in the field.
And so, what I've done is, I have a, kind of a, sharp spade here
with a, like a trenching shovel.
And, this will allow me to put a, kind of a,
little groove in the ground, where I can put the
Soil Moisture Sensor down into that groove.
And so, there's some technique to this.
And so, it is important to know how to be able to do this.
So, to start with, what I'm going to do is, basically,
open up a trench in the ground here.
So, I'm, just going to, kind of, press down a little bit there.
Kind of, open this up, just a little bit.
Just wide enough that I can get the Soil Moisture Sensor
down in there on it's side
And then, I will take the Soil Moisture Sensor,
and I place it down into the hole gently, on its side there.
And then, what I need to do is firm the soil up around the
sensor to the same compaction as the soil around it.
So, that may take a little bit to be able to compact it
back around there.
So, I just press down, kind of gently,
kind of pack it back in there.
And now, I have my reading.
Another thing to be careful with the Soil Moisture Sensor is
removal of the sensor from the ground.
Kind of, the natural inclination would be
just to grab the and yank it out.
You want to be careful, because if you've packed it down nicely,
it could be in there fairly tightly.
So, you may need to, kind of, dig it out a little bit, to be able
to get to it, so that you can, kind of, ease it out of the ground,
here, without yanking the wires.
So, we've seen how to place the
Soil Moisture Sensor out in the field.
What I've done here, is I have a plastic bin here, and I've put
some soil in here, and it's loose soil from the garden
And so, I'm going to use it to just be able to make some
measurements inside here.
So, I'm just going to put it down here.
And, I need to place the sensor into this soil,
much like I did out in the field.
Now, this is very loose soil, so it's going to go into a trench,
but because it's loose enough, I can actually, kind of, dig
kind of, a slightly trench here, and place it in there sideways.
Because, it's loose enough that I can actually do this.
And so, I'm going to place it down in there, like that.
And then, I will put the soil around it.
And then, like we said out there, it needs to be packed
down to about the same compaction as the soil around it,
to be able to do the measurement.
Now that I have the sensor in the soil,
I'm going to plug it into the LabQuest.
And now, I end up with a reading of…
I'm getting 9.3% there, or thereabouts.
So that's, my soil is fairly dry.
Some garden soil that I had.
And, so that, I could just read a meter, and be able to go
around and measure different values of soil at different places.
Often, like in this case, you might be interested
in just individual readings.
So, you might just read it off the meter itself at this point.
You could set it up, maybe, with a selected events mode,
where you would measure the soil moisture content, maybe,
in different areas if you wanted to.
You can do it over time if you wanted to.
So, this is where you might go in and set it up
for a long period of time.
Why don't I, at least, show you how you might do that one.
Set it up. We probably won't actually do a run on this one,
but we might set it up.
So, I'll show you how you do that.
Take a look at what the default collection parameters are though.
So, for this one it's a 'Time Based' / '1 sample per second' /
for '90.0 seconds'.
I might want to change that.
So, one use case might be to monitor the soil moisture
content over a period of time.
So, let's suppose I wanted to measure a sample for 24 hours.
And so, if I wanted to do that, I can go up and change that by
tapping on the collection parameters there.
'Time Based', I'll leave that the same.
Let me do this. Change my 'Duration'.
And, I want to do, say, '24' - Hours ('h').
And then, maybe I want to do, I don't know, '4' samples an hour,
once every 15 minutes. So, I can say 'Done'.
And then, I hit 'OK'.
And well, what happened now, is if I hit collect,
it would collect data for 24 hours, once every 15 minutes.
And, I might have a situation where I have a heat lamp,
or something, on my soil sample.
So, I'm drying it out,
and, could measure that effect over a period of time.
So, let’s remove this again from the soil here,
And, you need to be careful. You don't want these students
to just yank this out. We talked about that outside.
That so, we can dig it out here, pull it out here,
kind of, brush it off, and we’re good to go there.
So again, the Soil Moisture Sensor would be very useful
in agricultural setting, horticulture, biology.
And, this could be really nice in the situation where
students want to do some kind of inquiry activity.
Where they are monitoring the growth of a plant,
and using it to adjust the soil moisture content,
and to be able to do that.
So, you know, inquiry is big thing that is happening now.
And so, this would be a great sensor for those kinds of activities.