---
title: MANUAL - Apera PH20 pH Meter
canonical: https://fernland.com.au/documents/718/
dateModified: 2026-07-12 07:54:55
summary: Technical Sheet
type: tech_sheet
---

# MANUAL - Apera PH20 pH Meter

> Technical Sheet

PH20 Value pH Tester Kit
User Manual

APERA INSTRUMENTS, LLC

v 4.3

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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

Table of Contents
1. Battery Installation .................................................................................................................................1
2. Keypad Functions....................................................................................................................................1
3. What’s in the Kit? ...................................................................................................................................2
4. Preparation before Use ..........................................................................................................................2
5. Calibration ..............................................................................................................................................2
6. Measurement.........................................................................................................................................4
7. Parameter Setting...................................................................................................................................4
8. Common Problems.................................................................................................................................5
9. Technical Specifications..........................................................................................................................5
10. Icons and Functions................................................................................................................................6
11. Warranty.................................................................................................................................................6

■ 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 afterwards.

[Diagram: Illustration of a sensor shield being removed from and reattached to the probe]

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1. Battery Installation
Please install batteries according to the following steps. *Please note the correct direction of battery
installation:
The Positive Side (“+”) OF EVERY SINGLE Battery MUST FACE UP.
(WRONG INSTALLATION OF BATTERIES WILL CAUSE DAMAGE TO THE TESTER AND POTENTIAL HAZARDS!)

[Diagram: 7-step visual guide for installing 4 x AAA batteries]

2. Keypad Functions
■Short press-------  2 seconds

| | |
| :--- | :--- |
| [Power/Meas Icon] | 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; |
| [Cal/Enter Icon] | 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. |

[Diagram: Diagram - 1 showing the tester components: Battery Cap, LCD Display, Keypad, Probe Cap, pH Sensor]

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3. What’s in the Kit?
[Diagram - 2: Illustration of the kit contents including pH Tester, pH Buffer Solutions, and Lanyard]

4. 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 in 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 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.

5. Calibration
1) Short press [Power/Meas Icon] to turn on. Rinse in distilled water; use clean tissue to
dap off excess water.
2) Long press [Cal/Enter Icon] to enter calibration mode (short press [Power/Meas Icon] 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 1st point
calibration; Stir gently; leave it to stand; Wait for [Smiley Face Icon] to appear and stay
on the screen (see Diagram 3); short press [Cal/Enter Icon] to finish 1st point calibration; tester returns
to measurement mode; calibration icon [M] displays on button left side of the screen.

[Diagram - 3: Illustration of the LCD screen showing 6.6 pH and a smiley face]

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4) Rinse probe in distilled water. Long press [Cal/Enter Icon] to enter calibration mode; insert the probe in
the pH 4.00 calibration solution to start the 2nd point calibration, stir gently; leave it to stand;
wait for [Smiley Face Icon] to appear and stay on the screen; then short press [Cal/Enter Icon] to finish the 2nd point
calibration, tester returns to measuring mode, calibration icons [L] [M] display on bottom left.
5) Repeat step 4) and use 10.01 pH standard buffer (sold separately) to perform 3rd point
calibration. [L] [M] [H] will show up on 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 |
| :--- | :--- | :--- | :--- |
| 1-point Calibration | 7.00 pH | [M] | Required Accuracy≥ 0.3 pH |
| 2-point Calibration | 7.00 pH and 4.00 pH | [L] [M] | Target pH level 8.5 pH |
| 3-point Calibration | 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 ([Smiley Face Icon] is not staying on LCD), pressing [Cal/Enter Icon] will 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.

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6. Measurement
1) Short press [Power/Meas Icon] 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 [Smiley Face Icon] comes up and stays on 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 probe in purified water because that will cause permanent damage to the
pH electrode. Purified water is only recommended for rinsing the probe.

7. Parameter Setting
7.1 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 factory default setting (erase calibration record) | No – Yes | No |

7.2 Parameter Setting
When turned off, long press [Power/Meas Icon] to enter setup → short press [Power/Meas Icon] to switch P1-P2-P3→
Short press [Cal/Enter Icon], parameter flashing →short press [Power/Meas Icon] to choose, short press [Cal/Enter Icon] to confirm
parameter change →Long press [Power/Meas Icon] to go back to measurement mode.

7.3 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).

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| Icons | pH standard buffer series | |
| :--- | :--- | :--- |
| | USA series | NIST series |
| Three-Point calibration | [L] 4.00 pH | 4.01 pH |
| | [M] 7.00 pH | 6.86 pH |
| | [H] 10.01 pH | 9.18 pH |

8. Common Problems
The tester has self-diagnosis function to help you fix common problems:

| Symbol | Self-Diagnosis information | How to fix |
| :--- | :--- | :--- |
| Er 1 | 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 buffer is expired or contaminated.
3. Check if probe is damaged.
4. Check if there is any air bubble in the glass bulb sensor |
| Er 2 | [Cal/Enter Icon] Is pressed before measurement is stable ([Smiley Face Icon] appears and stays) | Wait for the smiley face to appear and stay, then press [Cal/Enter Icon] |

* 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

9. 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 |

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10. Icons and Functions
8.1 Calibration points indication: [L] [M] [H]
8.2 Stable Measurement: [Smiley Face Icon] appears and stays on the screen
8.3 Self-Diagnostic information: Er1, Er2
8.4 Low-Voltage warning: [Battery Icon] flashes, reminder of battery replacement
8.5 Auto Power-Off in 8 minutes if no operation.

11. Warranty
We warrant this instrument to be free from defects in material and workmanship and agree to
repair or replace free of charge, at option of APERA INSTRUMENTS, LLC, any malfunctioned or
damaged product attributable to 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 to perform 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.

APERA INSTRUMENTS, LLC
Address: 6656 Busch Blvd, Columbus Ohio 43229