AQUATERR INSTRUMENTS M-300 User manual

A QUATERR
I N S T R U M E N T S
M, T & EC -300
User’s Manual
Aquaterr Digital Soil Moisture, Temperature and Salinity
Meters

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A QUATERR
INSTRUMENTS
Leader in Portable Soil Measuring Technology

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It is important to read these SAFETY PRECAUTIONS before using the
M, T & EC -300 meters.
Always know what you are probing into. Be careful not to probe into power lines, drip tubing,
gas lines, and other objects that may be invisible from the surface.
Do not try to force the probe into rock or hard soil. The handle is provided to help in probe
removal, forcing may result in bending or breaking the probe or cause damage to the
sensing area. Sharp rocks can damage the sensor. To determine the moisture content of
areas with a hard cracked surface, first break through the hard layer with a shovel, and then
insert the probe, If the ground is still too hard, use an auger or a pipe to create the hole.
Do not hit the meter end. This may result in loss of calibration or destruction of your meter.
Do not cut the roots of plants, if avoidable. Insert the probe with the flat edges parallel to the
roots. Test the soil under plants by inserting the probe at an angle. Be especially careful of
the tap root, the major root running directly under the plant.
Do not leave the probe in the soil. If the probe is left in the ground, it can loose intimate
contact with the soil resulting in incorrect reading.
Guidebook
The Aquaterr Instruments Guidebook explains how to use your meter to optimize your
irrigation practices by helping you to look at the relationship between plants, soil and moisture.

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AQUATERR INSTRUMENTS
Moisture and Multimeter Owner’s Manual
Your patented Aquaterr Instruments Meter can assist you in effective soil-water
management. It is light weight and portable providing instantaneous moisture and salinity
readings in rapid succession at multiple sites and depths. It is virtually free from errors
ordinarily caused by temperature, pH, dissolved salts and metallic ions. However, its greatest
virtue is its ease of use.
This manual covers the Moisture Meter, the Temperature / Moisture Meter, and the
Temperature/Moisture/Salinity (E.C.) Multimeter.
GO TRY IT
Although the meter is a versatile, sophisticated instrument, it is easy to use. The first thing you
should do with your new meter is to calibrate the moisture, and then go ahead outside and try
it.
1. Choose a reasonably soft and moist area to start.
2, Gently insert the probe into the ground, six inches is enough.
3. Press the “MSTR” or “TEST” button on the front panel. The meter will respond with the soil
moisture reading.
4. Press the “TEMP” button and the meter will show you the soil temperature.
5. To read EC (Salinity Meter only), set the moisture calibration knob “W” (upper right corner),
to the moisture reading from step 3. Now press the “EC” button and after about 4
seconds, the salinity will be displayed.
6. Wipe the probe between tests.
NOTE: While your Meter was calibrated and tested before it left the factory, the Meter may
need calibration before the readings will be accurate. This manual will show you how easy it is
to calibrate and operate your new Meter. For the Salinity Multimeter, the Salinity calibration is
set at the factory and is very stable. It would be very rare for this unit to require calibration
after it leaves, please do this ONLY if you feel very certain that your readings are not accurate.

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FOUR CRITICAL STEPS
While your Meter is easy to use, four important steps must be performed to ensure
repeatable results.
1. CALIBRATE the moisture section in IRRIGATION water. Check its calibration every several
hours.
2. WIPE THE PROBE with a towel between EACH test, remove all excess dirt. Dirt carryover
will cause errors in future readings.
3. The probe tip (end 5 inches) must be in INTIMATE contact with the soil.
4. Test SEVERAL spots at EACH location, and then average the results.
CALIBRATING THE MOISTURE FUNCTION
Calibrating your Meter for moisture takes just a few seconds. The moisture calibration should
be performed before testing and at regular intervals during testing (once every several hours).
This will help ensure accuracy and repeatability of the tests.
1. Fully immerse the sensor end in IRRIGATION water, keeping the meter end out of the
water at all times. If you have very soft water (EC below 200 ppm or 30 ms), call technical
service for calibration recommendations.
2. While the probe is in the water, push the “MSTR” button (the only push button on the
Moisture Meters). While pushing down on the “MSTR” button, turn the “SET” knob until the
meter reads 100 (clockwise increases the meter reading).
3. The Moisture Meter is now ready to use.
MEASURING SOIL MOISTURE CONTENT
There are a couple of important things to remember when measuring the moisture content:
make sure the probe is contacting the soil and take several readings about one foot apart at
each location to make sure that there is not a problem with one location.
1. Push the probe into the soil to desired depth. If the ground is too hard, use an auger or a
piece of pipe to make a hole to the desired test depth, and then push the probe into the
soil. The sensing window must be in contact with the soil to get repeatable results.
2. Push the “MSTR” button. The meter reading indicates the soil moisture level.
3. WIPE off the probe with a towel between readings.

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COMMON PROBLEMS (Soil Moisture Measurements)
PROBLEMS
Widely varying readings, due to lack of Soil
Compaction caused by wiggling the probe.
Lower/higher than expected readings.
Probe in water, meter will not read 100.
SOLUTIONS
Insert probe, press the dirt around the
probe by standing close to both sides of the
probe. Then take reading.
Recalibrate the meter in irrigation water.
Change the battery. Remove battery cover
with a screw driver and replace the 9 volt
battery inside with a new one.
MEASURING SOIL SALINITY
With the sensor in air, push the “EC” button and wait until the “EC-ON” light illuminates. The EC
reading should be zero. If the reading is not zero, turn the upper left knob “CAL” until the
display shows a zero reading.
The Salinity Multimeter senses the salinity of the moisture component in the soil, thus the
more water present, the better the readings will be. The best time to take a reading is shortly
after irrigation. Also, make sure the sensor has intimate contact with the soil and take several
readings at each location. Make sure that the sensor has reached temperature equilibrium (in
the soil for two to three minutes) before calibrating, and recalibrate when temperature
changes occur.
1. Push the probe into the soil to the desired depth. If the ground is too hard use an auger.
The sensing window and wings must be in contact with the soil for repeatability.
2. Push the “MSTR” button. The reading is the soil moisture level. Set the moisture
compensation knob “W” (upper right corner) to the moisture level being displayed.
3. Push the “EC” button. After about 4 seconds the “EC–ON” light will illuminate and the
meter will read the salinity in µS. (microSiemens).
4. WIPE OFF the probe with a towel between readings. Soil carry-over (attached to sensor)
between readings can be a significant problem with salinity readings.
MEASURING LIQUID SALINITY
When measuring the salinity of a liquid with your Meter, the most accurate reading is made
when the liquid just covers the winged portion of the probe (about 4 inches (10cm) above the
tip). Make sure the sensor has reached temperature equilibrium with the liquid (in the liquid
for 2-3 minutes) before calibrating and is recalibrated whenever temperature changes occur.
1. Place sensor into the liquid.

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2. With the moisture calibration knob “W” (upper right side of meter) in the full clockwise
position, push the EC button. After about 4 seconds, the “EC-ON” light will illuminate and
the meter will read the salinity in µS (microSiemens).
3 WIPE OFF the sensor between readings.
MEASURING SOIL TEMPERATURE
(Available with Temperature and Temperature/Salinity Meters)
This is the easiest multimeter function to use. As with all of the other functions it is important
to have soil contact with the probe.
1. Push the probe into the ground until the temperature sensor is covered. This means
covering the entire winged section.
2. Wait until the sensor stabilizes (typically 2-3 minutes), and the sensor’s temperature
approaches the soil’s temperature. Generally, the more moisture in the soil, the faster the
sensor stabilizes.
3. Push the “TEMP” button. The meter reading indicates the sensor temperature.
4. WIPE OFF the probe between readings.
COMMOM PROBLEMS (Soil Temperature Measurements)
PROBLEMS
Sensor readings move slowly.
SOLUTION
The sensor gradually reaches equilibrium
with the soil. This is called an asymptotic
approach, meaning it moves fast at first,
and them slows down as it approaches
equilibrium. If you are taking other readings
(i.e. moisture), then take your temperature
readings last.

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EVALUATING THE MOISTURE MEASUREMENTS
It is important to remember that your Meter is a capacitance moisture meter. Capacitance
meters “look” at the air-water ratio in the soil. Thus, soil compaction has an affect on the
reading. A more compact soil will hold less air than a loose soil (like a sponge). This means
that the more compact soil will have higher readings than a loose soil. (See Guidebook for
further explanation). Also important is that your Meter is averaging the readings over the
entire sensor area. Thus, soil contact with the entire sensor is important.
When reading and interpreting the meter’s color coding you should remember that the coding
is only meant to serve as a reference. It does not provide an optimal guide for all plants in all
soil types during all stages of growth.
•Blue: Free water is present.
•Dark Green: Ample soil moisture exists for virtually all plant growth.
•Light Green: Water level is approaching stress conditions. For young, budding and
drought sensitive plants irrigate in the upper one half of the zone. Use the lower
end of the zone for mature and drought resistant plants.
•Yellow: Stress is apt to occur, although most plants will survive if water condition is
temporary.
•Orange: Damaging stress to most plants.
•Red: Permanent wilting and death is likely.
While the color coding should only be used as a reference, it points out that plant stress not
only depends on plant type and stage of growth, but also depends on soil types. Thus, the “C”,
“L” and “S” on the meter face indicate the reference color bands for Clay, Loam and Sandy
Loam, respectively.
EVALUATING THE SALINITY MEASUREMENTS (Salinity Multimeter)
Remember that you are taking a measurement of the salinity in the soil water. This is not the
same as finding the salinity of a solution extracted from the soil sample the way a lab does.
The difference is that the Salinity Multimeter measurements are evaluated at different soil
moisture levels. This means that:
•The measurement is what the roots are “seeing” now.
•Some salts, which do not dissolve as easily, might not be present in the soil water
which you are measuring.
•Salinity is more concentrated at lower moisture contents.

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COMMOM PROBLEMS (Soil Salinity Measurements)
PROBLEMS
Battery indicator is on
EC of soil matches EC of the water
Salinity is lower than expected
SOLUTIONS
Replace the battery quickly. Remove the
battery cover and replace with a 9 volt
battery.
Give more time for the soil to come to
equilibrium. Do not test so soon after
irrigation.
Check soil moisture level. If the soil
moisture level is below 65% the readings
need to be calibrated with a soil sampling
test. Salt will precipitate in the soil’s free
(available) water, and will saturate out in
this soil/water mixture. There is not
enough water present for the salts to mix
with the water evenly. For this reason, a
sample of the soil must be taken, then the
moisture and salt content of the soil
sample has to be determined, and the
results can be used to calibrate the “EC”
readings of the EC-300.
Salinity Multimeter PROBE CARE
It is important to keep the wings of the probe clean and free of dirt and buildup. It is suggested
that every couple of weeks, the wings be polished with a plastic abrasive pad to remove
buildup. When cleaning it is also important not to abrade the plastic area.

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CALIBRATING THE SALINITY FUNCTION (Salinity Multimeter)
Caution: This should only be done as a last resort after you have tried everything else and
you are certain that it is required.
We have provided two methods of calibrating the salinity function. The first method is more
convenient for laboratory or controlled conditions; the second is more convenient in the field.
The calibration knob “CAL” is located on the upper left hand side of the meter’s panel. Make
sure that the knob to the right of the meter’s panel “W” is turned the furthest clockwise
position for liquids and set to 100 for soils.
First Method:
Using a Bench Top Meter – If you have a calibrated bench-top or laboratory EC meter:
1. Prepare a water sample at or near the field EC using table salt and your bench top
meter.
2. Follow instructions for measuring liquid salinity. Remember to give the meter two to
three minutes to reach temperature equilibrium.
3. Compare the Multimeter meter reading to the bench top reading.
4. Adjust the Multimeter calibration knob “CAL” (left of the meter) until the meters
agree.
Second Method:
Air – This will set your meter to a repeatable value, but not to the accuracy which can be
obtained by calibration with a bench top meter.
1. Place the Multimeter in the sample and wait two or three minutes to reach
temperature equilibrium (the longer the better).
2. Quickly take the meter out of the sample, wipe off the tip and press EC button.
3. When the EC-ON light comes on adjust the calibration knob “CAL” (left of the
meter) until the Multimeter reads 0.1 in the air. This is the best starting point for
field use.
If neither of these methods work, remove the battery cover (four small Phillips head screws),
and carefully disconnect the battery cable from the battery. Then locate the coarse zero set
(see diagram), and using a small screwdriver, rotate the small screw counterclockwise to
increase, clockwise to decrease, and follow the above directions.

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SPECIFICATIONS
PROBE LENGTH: 30 Inches (76.2cm)
PROBE DIAMETER: !Inch (1.27cm)
PROBE CONSTRUCTION: Stainless Steel
OVERALL LENGTH: 36 Inches (approx.) (91.44cm)
TEMPERATURE RANGE: 4.44 to 65.55 deg. C
METER ACCURACY: 1% of full scale
POWER SOURCE: 9 volt battery
LIFE OF POWER SOURCE: Approx. 3 months
WEIGHT: Approx. 5 pounds (2.26Kg)
SCALE:
MOISTURE: 0 – 100%
TEMPERATURE: 0 – 199 deg F (0 – 92.77 deg C)
EC: 2000 µS (microSiemens)