Apera Instruments GroStar GS3 Premium User manual

GroStar™
GS3 Premium EC Pen Tester
User Manual
APERA INSTRUMENTS (Europe) GmbH
www.aperainst.de

1
Content
1Main Features ................................................................................................................ 1
2Preparation Before First Use .......................................................................................... 3
3EC Calibration................................................................................................................ 3
4EC/500ppm/700ppm Measurement................................................................................ 4
5Other Functions.............................................................................................................. 4
6Probe Cleaning............................................................................................................... 5
7Probe Storage................................................................................................................ 5
8Battery Replacement...................................................................................................... 6
9Probe Replacement........................................................................................................ 6
10 Notes.............................................................................................................................. 6
11 Troubleshooting Guide ................................................................................................... 7
12 Technical Specs............................................................................................................. 8
13 What’s in the box............................................................................................................ 9
14 Accessories.................................................................................................................... 9
15 Warranty......................................................................................................................... 9
Thank you for choosing the Apera GroStar™ GS3 Premium EC Pen Tester. This
premium pen has been designed specifically for the horticultural market. Since 1991,
Apera instruments has been dedicated to providing hi-tech, accurate, lab-grade
instruments and sensors. GroStar's intelligent design reduces the guesswork so you
can easily manage your crops success.
1 Main Features
•Premium titanium alloy conductivity probe measures EC, ppm (500/700) all-in-one
unit with minimal maintenance.
•Easy to use design and quick 1-point calibration adjustment.
•3-Color backlit LCD screen gives you clear readings in different modes even in dark
environment.
•Durable structure, IP67 waterproof rating, powered by AAA batteries.
•The probe is replaceable, so you don't have to discard the entire pen when the probe
reaches its end of life.

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3-Color LCD Screen
•White for measurement mode
•Green for calibration mode
•Red for calibration error
stands for stabilized
reading
M stands for successful
calibration: M is pH 7 or 2.77 EC.
The icon will disappear after 30
days to remind you for re-
calibration.
Probe Cap
•Water droplets are added
during production to maintain
the moisture of the probe. This
is normal practice and should
not be attributed to used
product.
•The fill line shows the level to
which you should pour the
soaking solution or sample
solution.
•For details of probe storage, see
Section 7.
Short Press
Long Press
1. Power on
2. Manual hold
Press again to
cancel hold.
Power off
In
measurement
mode, press to
turn on/off the
backlight.
Start
calibration
Switch mode:
EC→500ppm→
700ppm
Switch
between °F
and °C
Premium EC Probe
•Titanium alloy conductivity sensor,
highly accurate and requires
minimal maintenance.
•The probe is replaceable, saving
money in the long run.

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2 Preparation Before First Use
2.1 Pull out the battery insulation slip, and take off the probe cap.
2.2 Rinse off the probe in clean water, then shake off excess water.
2.3 Calibrate EC at 2.77 EC. For calibration tutorial, refer to Section 3.
3 EC Calibration
3.1 Power on and remove the probe cap. Rinse the probe with clean
water and shake-dry, then submerge it in the 2.77 EC standard
solution; shake the probe in the solution up and down for a
few seconds to remove potential air bubbles, then let it stand.
3.2 Hold until screen turns green. The pen starts automatic
calibration. Wait for "Good" to show up (in 10-15 seconds),
indicating the calibration is completed, then the pen returns to
measurement mode.
Short press any key while calibrating (in green screen) to cancel calibration and return to
measurement.
3.3 icon will show up on the lower left corner indicating the
tester is successfully calibrated. will disappear in 30 days
after calibration, reminding you to re-calibrate EC. We
recommend calibrating the EC once every month to ensure the
accuracy. If you feel like the accuracy might be off, simply test

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the standard solution (make sure the standard is fresh and clean). If the reading is
greater than 2.8 EC or smaller than 2.7 EC, then it’s time to calibrate again.
3.4 If the calibration fails, the screen will turn red. For details, see
Section 11 Troubleshooting Guide.
4 EC/500ppm/700ppm Measurement
4.1 Power on and remove the probe cap.
4.2 Rinse the probe with clean water and shake off excess water.
4.3 Submerge the probe into the solution, make a quick stir to remove
potential air bubbles around the sensor. Hold still and wait for the
reading to stabilize ( stays on the screen), then record the
reading.
4.4 Short press to switch from EC → 500ppm → 700ppm
4.5 Thoroughly rinse off the probe with clean water.
What is EC and its relation to 500ppm & 700ppm?
EC (electrical conductivity) is a measure of the nutrients in the solution. Low conductivity
implies a low nutrient concentration, which usually results in nutritional deficiencies and slow
growth rates of your plants.
A higher conductivity is more food for your plants. However, be careful of very high levels as
delicate plants, cuttings, and seedlings can experience fertilizer burn if the conductivity is
excessively high.
EC, 500ppm, and 700ppm are simply different units preferred by different markets. 500ppm
and 700ppm both originate from EC. Therefore, using EC to compare and analyze test result
is the safest way and will minimize confusion. Here is how they convert to each other:
1.0 (EC) = 500ppm (500ppm) = 700ppm (700ppm)
2.6 (EC) = 1300ppm (500ppm) = 1820ppm (700ppm)
3.5 (EC) = 1750ppm (500ppm) = 2450ppm (700ppm)
5 Other Functions
5.1 If necessary, you can manually hold (lock) the reading by short pressing . Press it
again to cancel the hold.
5.2 Long press to switch temp. unit between °F and °C.

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5.3 The tester will automatically power off if there is no operation
within 10 minutes. If you want to turn off/on the Auto. Power Off
function, power off the tester, and then hold for 5 seconds
until you see Auto Off or Auto On. Then it will power on and go
to measurement mode automatically.
6 Probe Cleaning
6.1 The tester is only as accurate as the probe is clean. Always thoroughly rinse off the
probe before and after each measurement with clean water in a container or with a
wash bottle.
6.2 For tough contaminants, remove the sensor shield, soak the probe in Apera’s cleaning
solution or detergent water for 30 minutes. Then use a soft brush to remove the
contaminants. Afterwards, rinse it off, then re-calibrate the tester before using again.
7 Probe Storage
7.1 Under regular usage (daily or weekly use), as long as there are some
water droplets in the probe cap, you are good to go.
7.2 For long-term storage (you are not going to use the product for a
while), add clean water to the Fill line in the cap and store the probe in
it. Close the probe cap tightly.
or

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8 Battery Replacement
①Pull up the battery cap (might take some force).
②Slide the battery cover along the OPEN arrow to open the cover.
③Open the battery cover.
④Insert the batteries (ALL POSITIVE SIDES FACING UP).
⑤Press down the battery cover and hold it.
⑥Slide the battery cover along the LOCK arrow to lock the cover.
⑦Close the battery cap. Make sure to push it all the way down. The tester’s waterproof
rating may be compromised if the battery cap is not tightly closed.
9 Probe Replacement
•Screw off the probe ring, unplug the old probe; plug in the new
probe (make sure to align the connector's position properly), and
screw on the probe ring.
Probes don’t last forever. Every probe will eventually age and fail even
if you don't use it that often. The typical service life of GroStar probes
is 18-24 months depending on the frequency of usage and how well you keep it clean and
properly stored.
We recommend replacing your probe at least every 18 months to ensure the best accuracy.
The nice thing about GroStar pens is that you can just buy a replacement probe instead of a
whole new tester.
10 Notes
10.1 Avoid testing in high (>113°F/ 45°C) or low temperature (<41°F/ 5°C) solutions as it will
cause greater measurement error and damage to the probe. Test your samples and
perform calibration close to room temperature as much as possible.
10.2 Make sure the battery cap is completely closed with the O-ring. Otherwise, the
waterproof rating could be compromised.

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11 Troubleshooting Guide
Trouble
Reason
How to fix
Cannot calibrate
Poor quality standard
solutions
Replace with fresh and clean standard calibration
solutions made by legitimate scientific instrument
manufacturers.
Contaminated probe
Clean the probe with Apera’s cleaning solution or
detergent water.
Aged probe
Replace the probe.
Dried-out probe
Soak the probe in clean water for 30 minutes.
Probe is not fully
submerged in the
solution
Make sure the probe is fully immersed in the solution at
least 1 inch deep.
Air bubbles around the
sensor
Make a quick stir in the solution to remove air bubbles.
Reading is always
slowly changing,
won’t stabilize.
Contaminated probe
Clean the probe with Apera’s cleaning solution or
detergent water.
Aged probe
Replace the probe.
Display similar
readings in any
solutions
Broken probe
If you don’t find any visible damage of the probe and it’s
within the 1-year probe warranty, contact your point of
purchase for warranty fulfillment; If there is visible
damage or the probe is more than 1-year old, replace
the probe.
Reading keeps
jumping
Probe is not fully
submerged in the
solution
Make sure the probe is fully immersed in the solution at
least 1 inch deep.
Air bubbles around the
sensor
Make a quick stir in the solution to remove air bubbles.
Probe is not properly
connected, or the pin
connector is broken.
Check the probe’s connector, make sure it’s not broken
and is correctly connected. Align the probe and
instrument correctly before plugging in. Never force it.
Ensure that the probe connector is not exposed in the
air too long.
Calibration is
successful, but
reading is not
accurate
Aged probe
Replace the probe.
Air bubbles around the
sensor
Make a quick stir in the solution to remove air bubbles.
Comparison with other
testers
To compare with other testers, make sure to perform
calibration for all testers in the same standards, then
test a 2nd point. Whichever gives more accurate
reading in the 2nd point standard is the most accurate
one.

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Out of range reminder for EC
Out of range reminder for temperature
12 Technical Specs
Range
0 to 10.0 EC,
0 to 7000ppm (700ppm),
0 to 5000ppm (500ppm),
0 to 50˚C (32 to 122˚F)
Resolution
0.1 EC, 10ppm (700ppm), 10ppm(500ppm), 0.1˚F/0.1˚C
Accuracy
±0.1 EC
±30ppm (500ppm)
±40ppm (700ppm)
±1˚C/±1˚F
Temperature compensation
Automatic
Calibration
automatic 1 point (2.77 EC)
Unit
EC, 500ppm, 700ppm, ˚F, ˚C
Power Supply
4-AAA alkaline batteries
Backlight
White (measurement); Green (calibration); Red (errors)
Reading hold
Manual
Warranty
Two years for the instrument, one year for the probe
EC probe
Titanium alloy
Successful calibration
indicators
M (2.77 EC)
Low battery reminder
Waterproof rating
IP67
Reading stabilization icon

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13 What’s in the box
14 Accessories
•pH buffer Kit (pH4/7, 250ml, each), item AI1113
•pH buffer Kit (pH4/7/10, 250ml, each), item AI1115
•2.77 EC Standard Calibration Solution
•3M KCl storage solution 250ml, item Al1107
•GS3-E EC Probe, item Al58030
15 Warranty
How Long Does the Coverage Last?
Apera Instruments® (Apera) warrants the GroStar™ GS4 Premium pH/EC Combo Pen
Tester (Product) for a period of 24 months for the instrument and 12 months for the probe
from date of purchase by original purchaser or consumer. Proof of purchase is required for
the warranty to be effective (store sales receipt for Product showing model number, payment,
and date of purchase). This warranty is non-transferable and terminates if the original
purchaser/consumer sells or transfers the Product a third party.
What is Covered?
Apera warrants the Product against defects in material and workmanship when used in a
normal manner, in accordance with Apera instruction manuals. If Apera is provided with valid
proof of purchase (as defined above) and determines the Product is defective, Apera may, in
its sole discretion either (a) repair the Product with new or refurbished parts, or (b) replace
the Product with a new or refurbished Product.
GS3 EC Pen
Laynard
2.77 EC
Solution

10
What is NOT Covered?
This warranty does not apply to equipment, component or part that was not manufactured or
sold by Apera and shall be void if any such item is installed on a Product. Further, this
warranty does not apply to replacement of items subject to normal use, wear and tear and
expressly excludes:
•Cosmetic damage such as stains, scratches, and dents
•Damage due to accident, improper use, negligence, careless operation or handling of
Product not in accordance with Apera instruction manuals, or failure to maintain or care
for Product as recommended by Apera
•Damage caused by use of parts not assembled/installed as per Apera instructions
•Damage caused by use of parts or accessories not produced or recommended by Apera
•Damage due to transportation or shipment of Product
•Product repaired or altered by parties other than Apera or its authorized agents
•Product with defaced, missing, or illegible serial numbers
•Products not purchased from Apera or an Apera-authorized distributor or reseller.
How Do You Get Service?
To begin a warranty claim you must return the Product to the point of purchase with valid
proof of purchase.
Limitation of Liability & Acknowledgments
TO THE MAXIMUM EXTENT PERMITTED BY LAW, THIS WARRANTY AND THE
REMEDIES SET OUT ABOVE ARE EXCLUSIVE AND IN LIEU OF ALL OTHER
WARRANTIES, GUARANTEES AND REMEDIES (ORAL OR WRITTEN, EXPRESS OR
IMPLIED). EXCEPT AS PROVIDED IN THIS WARRANTY AND TO THE MAXIMUM
EXTENT PERMITTED BY LAW, APERA INSTRUMENTS IS NOT RESPONSIBLE FOR
SPECIAL, INCIDENTIAL OR CONSEQUENTIAL LOSS OR DAMAGES, OR ANY OTHER
LOSS OR DAMAGES RESULTING FROM SALE OR USE OF THE PRODUCT, OR
BREACH OF WARRANTY, HOWEVER CAUSED, INCLUDING DAMAGES FOR LOST
PROFITS, PERSONAL INJURY OR PROPERTY DAMAGE.
IT IS UNDERSTOOD AND AGREED BY CONSUMER UPON PURCHASE OF A PRODUCT
THAT, EXCEPT AS STATED IN THIS WARRANTY, APERA INSTRUMENTS IS NOT
MAKING AND HAS NOT MADE ANY EXPRESS OR IMPLIED WARRANTY OR OTHER
REPRESENTATION REGARDING THE PRODUCT AND DISCLAIMS ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE TO THE EXTENT
PERMITTED BY LAW. ANY WARRANTIES WHICH ARE IMPOSED BY LAW AND CANNOT
BE DISCLAIMED ARE HEREBY LIMITED IN DURATION TO THE PERIOD AND
REMEDIES PROVIDED IN THIS WARRANTY.

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SOME JURISDICTIONS (STATES OR COUNTRIES) DO NOT ALLOW EXCLUSION OR
LIMITATION FOR INCIDENTIAL OR CONSEQUENTIAL DAMAGES, OR LIMITATION ON
HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE LIMITATION OR
EXCLUSION MAY NOT BE APPLICABLE. IF ANY PROVISION OF THIS WARRANTY IS
JUDGED TO BE ILLEGAL, INVALID OR UNENFORCEABLE, THE REMAINING
PROVISIONS OF THE WARRANTY SHALL REMAIN IN FULL FORCE AND EFFECT.
Governing Law; Authority
This warranty is governed by the laws of the state of country where Product is purchased,
without regard to its choice of law principles. Except as allowed by law, Apera does not limit
or exclude other rights a consumer may have with regard to the Product. No Apera
distributor, employee or agent is authorized to modify, extend, or otherwise change the terms
of this warranty.
APERA INSTRUMENTS (Europe) GmbH
Wilhelm-Muthmann-Straße 18
42329 Wuppertal, Germany
Contact: [e-mail]
Website: www.aperainst.de
Tel. [phone]