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APERA PH20 Value pH Tester Kit Manual

APERA PH20 Value pH Tester Kit Manual Image

PH20 Value pH Tester Kit
User Manual


Thank you for purchasing the Apera Instruments PH20 Pocket pH Tester Kit. Please read this manual carefully before use in order to properly use and maintain the product.
For video tutorials, please go to support.aperainst.com

■ Latest Upgrade
The latest PH20 Tester comes with an upgraded probe structure, which is equipped with a sensor shield that prevents the glass sensor breakage from accidental collisions (see picture below). Users can remove the shield when rinsing and cleaning the sensor and put it back on afterward.

Battery Installation

Please install batteries according to the following steps. *Please note the correct direction of the battery installation:
The Positive Side (“+”) OF EVERY SINGLE Battery MUST FACE UP.

Keypad Functions

■Short press——- < 2 seconds
■Long press——– > 2 seconds

1. Short press to turn on, long press to turn off;
2: When turned off, long press to enter setup;
3: In settings, short press to change parameter;
1.When turned on, long press to enter calibration mode.
2.In calibration mode, short press to finish calibration;
3.In settings, short press to confirm changes.

 What’s in the Kit?

Preparation before Use

Things needed in addition to what’s in the box
A cup of distilled water (8-16oz) for rinsing the probe, and clean tissue paper for removing excess water.
■ Note
Before shipment, the factory adds some water droplets to the tester’s cap to maintain a hydrated atmosphere for the probe. This ensures that the pH sensor keeps its sensitivity.
Therefore, users can begin using their tester immediately upon receiving it. This practice of adding several drops of water into the cap is highly recommended for frequent users when storing the tester. However, if the tester has not been used for a long time (e.g. > 1 month) and doesn’t perform as well as it used to be, users can soak it in a 3M KCL  (SKU: AI1107) solution overnight to recover its sensitivity.

* DO NOT use any other brand’s storage solutions because different chemicals may be used and potential damage could be caused to the probe.


1) Short press to turn on. Rinse in distilled water; use a clean tissue to dap off excess water.
2) Long pressCall to enter calibration mode (short press to go back to measurement mode if you want to cancel the calibration).
3) Insert the probe in the 7.00 pH calibration solution to start 1 st point calibration; Stir gently; leave it to stand; Wait for Stir gently to appear and stay on the screen (see Diagram 3);  short pressCall to finish 1st point calibration; tester returns to measurement mode; calibration M icon displays on the button left side of the screen.
4) Rinse the probe in distilled water. Long press Callto enter calibration mode; insert the probe in the pH 4.00 calibration solution to start the 2 nd point calibration, stir gently; leave it to stand; wait for to appear and stay on the screen; then short pressCall to finish the 2nd point calibration, tester returns to measuring mode, calibration icons L M display on the bottom left.
5) Repeat step 4) and use 10.01 pH standard buffer (sold separately) to perform 3 rd point calibration L M H. will show up on the bottom left.

■ Notes
a) Tester will automatically recognize pH buffer solution, users can choose calibration points: 1 point, 2 points, or 3 points. But the 1st point calibration must be in calibration solution of 7.00 pH, then followed by 2nd or 3rd point calibration. For details, please refer to the following table:

Calibration Solution Calibration icon When to do
7.00 pH M Required Accuracy.? 0.3 pH
7.00 pH and 4.00 pH  L M Target pH level< 8.5 pH
7.00 pH and 10.01 pH  L  M Target pH level> 8.5 pH
7.00 pH, 4.00 pH
and 10.01 pH
L M H  Wide measuring range

b) Automatic self-diagnostic information: In calibration mode, when the measured value hasn`t been stable yet (Stir gently is not staying on LCD), pressing Callwill cause LCD to display
“Er2”). For more details, please refer to Section 8.
c) Only pH 4.00 and pH 7.00 buffer solutions are included in the test kit, pH 10.01 is not.
Users can purchase it separately if needed (when your target pH level is >8.5 pH).
d) Keeping the standard calibration buffers in good condition is the foundation of taking reliable pH measurements. The bottled buffers (2 oz.) can be used for about 10 times as long as they are not contaminated (make sure they are tightly closed when not in use).
After that, we recommend replacing them with fresh ones to keep the accuracy.


  1. Short press to turn on the tester. Rinse the probe in distilled water. Then shake off excess water and dap with tissue paper.
  2. Stir the probe in your sample solution to accelerate stabilization and leave it to stand.
    Record the readings after Stir gentlycomes up and stays on the screen.

■ Notes
a) After each test, users should rinse the pH probe thoroughly with distilled water or purified water and remove excess water before the next test. Warm soap water and a
soft brush can be used to remove tough contaminants on the glass sensor.
b) When testing purified water like RO water or distilled water, it will take longer for the readings to get fully stabilized (typically 2-5 minutes).
c) Do NOT store the probe in purified water because that will cause permanent damage to the pH electrode. Purified water is only recommended for rinsing the probe.

Parameter Setting

Settings table

Prompt Mark Parameter Setting Content Code Factory
Default Setting
P1 Select pH buffer series USA — NIST USA
P2 Select temperature unit °F — °C °F
P3 Back to the factory default setting
(erase calibration record)
No — Yes No

Parameter Setting

When turned off, long press to enter setup → short pressCall to switch P1-P2-P3→ Short press, parameter flashing →short press to choose, short pressCall to confirm parameter change →Long press to go back to measurement mode.

Parameter Setting Instruction

Select standard pH buffer solution (P1): There are two options of standard buffer solutions: USA series and NIST series (refer details to the following table).

Icons pH standard buffer series
USA series NIST series
Three-Point calibration L 4.00 pH 4.01 pH
7.00 pH 6.86 pH
H   10.01 pH 9.18 pH

Common Problems

The tester has a self-diagnosis function to help you fix common problems:

Symbol Self-Diagnosis information How to fix
Wrong pH calibration solution, which exceeds the recognizable range of the meter. 1.  Check if the correct buffer is used (1st point calibration must be 7.00 pH).
2.Check if the buffer is expired or contaminated.
3. Check if the probe is damaged.
4. Check if there is an air bubble in the glass bulb sensor
APERA PH20 Value pH -measurement CallIs pressed before the measurement is stable ( e) appears and stays) Wait for the smiley face to appear and stay, then pressCall.

* If any air bubbles are found inside the sensor shield, shake the probe in sample solution with force to remove them. The existence of air bubbles will cause unstable measurements.

* For more FAQs, go to support.aperainst.com

Technical Specifications

pH Range 0 — 14.0 pH
Resolution 0.1 pH
Accuracy ±0.1 pH
Calibration Points 1 — 3 points
Automatic Temperature Compensation 0 — 50°C (32 — 122°F)
Temperature Range 0 — 50°C (32 — 122°F)
Resolution 0.1 °C
Accuracy ±0.5°C

Icons and Functions

8.1 Calibration points indication: L M H 
8.2 Stable Measurement: Stir gentlyappears and stays on the screen
8.3 Self-Diagnostic information: Er1, Er2
8.4 Low-Voltage warning: flashes, a reminder of battery replacement  Low-Voltage
8.5 Auto Power-Off in 8 minutes if no operation.


We warrant this instrument to be free from defects in material and workmanship and agree to repair or replace free of charge, at the option of APERA INSTRUMENTS, LLC,   any malfunctioned or damaged product attributable to the responsibility of APERA INSTRUMENTS, LLC for a period of TWO YEARS (SIX MONTHS for the probe) from the delivery. This limited warranty does not cover any damages due to: Transportation, storage, improper use, failure to follow the product instructions or performing any
preventive maintenance, modifications, combination or use with any products, materials, processes, systems or other matter not provided or authorized in writing by us,  unauthorized repair, normal wear, and tear, or external causes such as accidents, abuse, or other actions or events beyond our reasonable control.

Address: 6656 Busch Blvd, Columbus Ohio 43229
Tel: 1-614-285-3080
Email: [email protected]
Website: aperainst.com