APERA INSTRUMENTS PH60Z-VS Smart pH Meter for Viscous Samples

User Manual

Fluid Precision since 1991

Introduction

Thank you for choosing Apera Instruments. The PH60Z-VS pH Meter with LabSen® 855 Pre-pressurized pH/temp. electrode is designed for measuring the pH of viscous liquid samples such as skin care products, coatings, resin, honey, etc. It also performs well in general water solutions.

ATTENTION

NEVER use the product when it's freezing cold. Allow it to warm to room temperature before using.
NEVER use your finger to touch the pH glass membrane or use other materials to rub it, as this could generate static electricity and cause measurement errors. To remove excess water on the electrode, simply shake it off or blot dry with a Kimwipe or lint-free cloth.

Connecting with ZenTest® Mobile App

Download the latest ZenTest App from the Apple App Store or Google Play Store. Ensure your phone's Bluetooth is turned on. In the ZenTest App, tap the [Connect] icon [Bluetooth icon] on the upper right corner, then select your meter to connect (do NOT select the Demo device).

This user manual focuses on operating the meter via its keypad. For guides on using the ZenTest App for more functions, please refer to video tutorials (available via QR code in the original document).

1. What's in the kit

User Manual
LabSen 855 pH Electrode
PH60-Z pH Meter
CalBox Organizer
pH 4.00 Calibration Solution
pH 7.00 Calibration Solution
pH 10.01 Calibration Solution
3M KCl Soaking Solution
Protective Cap

2. Keypad Functions

Short Press: Less than 2 seconds

Long Press: Greater than 2 seconds

Button	Action	Description
[MEAS]	Short Press	Turn on the tester.
[MEAS]	Long Press	Turn off the tester.
[MEAS]	When turned off, Long Press	Enter parameter settings.
[MEAS]	In measurement mode, Short Press	Turn on backlight.
[MEAS]	In calibration mode, Short Press	Cancel calibration.
[MODE]	In measurement mode, Short Press	Switch between pH and mV measurement mode. (ORP Sensor is separately available)
[MODE]	In parameter settings, Short Press	Change parameters (Unidirectional).
[CAL]	Long Press	Enter calibration mode.
[CAL]	In calibration mode, Short Press	Confirm calibration.
[CAL]	When reading is locked (auto. HOLD on), Short Press	Unlock reading.

3. Preparation Before Use

3.1 LabSen 855 Electrode Structure

The electrode features an 8-pin connector with a connector locking ring, a storage vial, and a vial locking ring. The junction and pH glass membrane are critical components.

3.2 Preparation Steps

Pull out the battery insulation paper.
Loosen the storage vial locking ring by twisting it counterclockwise, then slowly pull out the electrode.
Place the storage vial (containing soaking solution) in the center of the CalBox solution organizer to prevent spills.
Rinse the electrode with pure water (preferably distilled or deionized water; RO water is an alternative). Blot dry the electrode with a Kimwipe or clean tissues to remove excess water, ensuring NOT to rub the glass membrane.
Perform at least a 2-point calibration before first-time use. Refer to Section 4 for calibration details.

4. pH Calibration

4.1 How to calibrate:

Short press [MEAS] to power on the meter.
Pour pH buffer solutions into the CalBox. Dip the electrode into pH 7.00 solution first, stir briefly, and let it stand.
Long press [CAL] to enter calibration mode. The screen will turn green. (Short press [MEAS] to quit calibration and return to measurement mode).
Wait for the reading to stabilize (indicated by a stable [CAL] icon on the screen). Then, short press [CAL] again to finish the first point calibration. The meter switches to measuring mode, and [M] will appear at the bottom left, indicating a successful 1-point calibration.
To calibrate the 2nd point, repeat steps 4.1.3 to 4.1.5 using the 4.00 pH calibration solution. Do NOT turn off the meter after the 7 pH calibration. If [L] is displayed next to [M], a successful 2-point calibration is complete.
If necessary (target pH value > 8.00), calibrate the 3rd point with the 10.01 pH calibration solution, repeating steps 4.1.3 to 4.1.5. If [H] is displayed next to [L] and [M], a successful 3-point calibration is indicated.

4.2 Notes about calibration

Always start calibration with pH 7.00. Perform the 2nd and 3rd point calibrations immediately after the 1st point. Do NOT turn off the meter before completing the second or third point. Failure to do so may result in an 'Er1' error upon restarting and requiring recalibration with pH 7.00. Refer to Section 14 for troubleshooting.
pH 4.00 and pH 7.00 buffer solutions in the CalBox can be used up to 10 times if not contaminated and the CalBox is capped. pH 10.01 can be used up to 5 times before its accuracy diminishes. Replace buffer solutions regularly to maintain accuracy.
Isothermal Measurement Principle: Automatic temperature compensation is insufficient for all pH measurement errors caused by temperature changes. For the most accurate measurement, calibrate the meter in buffer solutions at the same temperature as the sample solution.
The tester supports 1 to 3 points of automatic calibration and recognizes 5 types of pH standard solutions.

Calibration Standards and Accuracy

Calibration	USA Standard Series	NIST Standard Series	Icon	Recommended Accuracy
1-point	7.00 pH	6.86 pH	[M]	≥ ±0.1 pH
2-point	Option A: 1st pt: 7.00 pH 2nd pt: 4.00 pH or 1.68 pH	Option A: 1st pt: 6.86 pH 2nd pt: 4.01 pH or 1.68 pH	[L] [M]	Range < 7.00 pH
2-point	Option B: 1st pt: 7.00 pH 2nd pt: 10.01 pH or 12.45 pH	Option B: 1st pt: 6.86 pH 2nd pt: 9.18 pH or 12.45 pH	[M] [H]	Range >7.00 pH
3-point	1st pt: 7.00 pH 2nd pt: 4.00 or 1.68 pH 3rd pt: 10.01 or 12.45 pH	1st pt: 6.86 pH 2nd pt: 4.01 or 1.68 pH 3rd pt: 9.18 or 12.45 pH	[L] [M] [H]	Range: 0 to 14.00 pH

4.3 How often to calibrate the electrode?

Calibration frequency depends on sample type, electrode condition, and accuracy requirements. For high-accuracy measurements (≤ ±0.02pH), calibrate before every test. For general-accuracy measurements (≤ ±0.1 pH), calibrate every 1-2 weeks.

The electrode must be re-calibrated in the following cases:

The electrode hasn't been used for a long time or a different electrode is connected.
After measuring strong acid (pH<2) or strong base (pH>12) solutions.
After measuring fluoride-containing or strong organic solutions.
There is a significant temperature difference between the test sample and the buffer solution.

5. pH Measurement

5.1 How to Take pH Measurement

Short press [MEAS] to power on. Remove the storage sleeve and rinse the electrode in distilled/deionized water. Shake off excess water.
The LabSen 246-5 pH electrode can measure samples as low as 60 µL using the included semi-micro container. Ensure the sample solution level submerges the electrode's junction (white spot). Record the measured value after it has stabilized (indicated by a stable [MEAS] icon on the screen).
When measuring high-temperature solutions, calibrate the pH electrode at the same temperature as your test sample to minimize measurement error.
If necessary, enable the Auto-Hold function (refer to Section 8.3.3). The reading will lock automatically when stable for over 10 seconds, displaying a [HOLD] icon. Short press [ENT] to cancel Auto-Hold and continue measuring.

6. Electrode Cleaning

Maintain electrode cleanliness for accurate measurements. Rinse the electrode thoroughly with distilled or deionized water before and after each measurement. Shake off excess water or blot dry with a Kimwipe or lint-free cloth. Never rub the glass membrane to avoid static electricity and measurement errors.

Cleaning Procedures for Tough Contaminants

Type of Contamination	Cleaning Agent	Soaking Time
Lipophilic substances (e.g., oil and fat deposits)	Home dish soap water	5 – 10 minutes
Proteins	Apera Electrode Cleaning Solution (SKU: AI1166)	30 – 60 minutes
Inorganic coatings (e.g., hydrocarbons)	Commercially available glass cleaning solutions	5 – 10 minutes
Hard, scale-type calcium deposits	Apera Electrode Cleaning Solution (SKU: AI1166)	5 – 10 minutes
Alkaline coatings	Apera Electrode Cleaning Solution (SKU: AI1166)	5 – 10 minutes
Acidic coatings	0.1M NaOH solution	5 – 10 minutes
Sulfide-containing substances	Thiourea	30 – 60 minutes, until junction discoloration disappears.
Unknown substances	Apera Electrode Cleaning Solution (SKU: AI1166)	30 – 60 minutes

Use a soft brush to thoroughly clean contaminants. After cleaning, soak the pH electrode in 3M KCl solution for 12-24 hours for rehydration. Re-calibration is necessary before a new pH measurement.

7. Electrode Storage

Add 3M KCL soaking solution to the electrode storage vial and store the electrode in it. Twist the vial locking ring tightly. Replace the soaking solution monthly or if contaminated.
White crystals forming outside the storage vial are normal crystallization of the 3M KCL solution. Rinse them off and add fresh solution.
NEVER store the electrode in pure water (tap, RO, distilled, or deionized) as it can damage the electrode. If this occurs, soak the electrode in 3M KCL soaking solution overnight and re-calibrate before use.

8. Parameter Settings

8.1 Settings Menu

Parameter	Parameter Setting Contents	Code	Factory Default
P1	Select pH buffer standard	USA – NIST	USA
P2	Low value measurement alarm setting	0 to 14.00pH	0 pH
P3	High value measurement alarm setting	0 to 14.00pH	14.00 pH
P4	Auto. Hold	Off – On	Off
P5	Select backlight	Off – 1 – On	1
P6	Select temperature unit	°C – °F	°F
P7	Restore to factory default	No – Yes	No

8.2 Parameter Settings Navigation

When the meter is off, long press [MEAS] to enter parameter settings. Short press [MODE] to cycle through P1-P7. Short press [CAL] to select a parameter (it will start flickering). Short press [MODE] to change the parameter. Short press [CAL] to confirm the change. Long press [MEAS] to return to measurement mode.

8.3 Parameter Setting Instruction

8.3.1 Standard pH Buffer Series (P1):

Choose between USA series and NIST series. The factory default is USA series (see Section 4.2 for details).

8.3.2 Alarm Function (P2&P3)

Alarm triggered when reading ≤ 3.20 pH: Set P2 to 3.20 pH and P3 to 14.00 pH. The screen turns red when the stable reading is less than 3.20 pH.
Alarm triggered when reading ≥ 8.60 pH: Set P3 to 8.60 pH and P2 to 0.00 pH. The screen turns red when the stable reading is greater than 8.60 pH.
Alarm triggered when reading ≤ 3.20 pH or ≥ 8.60 pH: Set P2 to 3.20 pH and P3 to 8.60 pH. The screen turns red when the stable reading is less than 3.20 pH or greater than 8.60 pH.

9. Technical Specifications (Instrument)

Parameter	Specification
pH	Range: -2.00 – 16.00 pH
	Resolution: 0.01 pH
	Accuracy: ±0.01 pH (±1 digit)
	Calibration Points: 1 – 3 points
Temp.	Automatic Temperature Compensation (ATC): 0 – 50 °C (32 – 122 °F)
	Measuring Range: 0 – 50 °C (32 – 122 °F)
	Resolution: 0.1 °C
Accuracy	±0.5 °C
Screen	3-color LCD screen (Blue: Measurement; Green: Calibration; Red: Alarm)
Reading Lock	[HOLD] icon appears on screen.
Low-Voltage Warning	Flashing indicator for battery replacement needed.
Auto. Power-Off	In 8 minutes without operation.
Waterproof Rating	[IP67 Waterproof]
Power	DC3V, 4 x AAA alkaline batteries.
Battery Life	Operation up to 2000 hours.
Dimension & Weight	Tester: 40×40×178mm / 133g; Case: 255×210×50mm / 700g

10. Technical Specifications (Electrode)

Parameter	Specification
Measurement Range	0 – 14 pH
Temperature Range	0 to 130°C (32 to 266°F)
Reference System	Silver Ion Trap System
Junction	Ceramic
Reference Electrolyte	Pre-pressurized Gel KCl
Shaft Dimension	12*120mm
Membrane Impedence	<500MΩ
Temperature Sensor	30KΩ NTC

11. Electrode Replacement

pH electrodes have a service life of 1-2 years, depending on usage and maintenance. Replacing the electrode every 1-2 years is recommended for optimal performance.

11.2 Disconnect the old electrode

Step 1: Loosen the connector ring to unlock the connection. Step 2: Hold the connector ring and pull off directly. Never twist the black rubber part to prevent damage.

11.3 Install the new electrode

Step 1: Align the notch, hold the connector locking ring, and push in directly. Step 2: Tighten the connector ring to lock the connection.

After installing a new electrode, perform at least a 2-point calibration (refer to Section 4.1).

11.5 pH Electrodes Compatible with the Meter for Other Applications

LabSen 335 pH/Temp. Electrode for wastewater, suspensions, and emulsions
LabSen 246-5 pH/Temp. Electrode for small-volume solutions and test tubes
LabSen 845 pH/Temp. Electrode for strong alkaline and high-salinity solutions
LabSen 835 pH/Temp. Electrode for HF-containing and strong acidic solutions
LabSen 865 pH/Temp. Electrode for high temperature and caustic solutions
LabSen 855 pH/Temp. Electrode for viscous samples
LabSen 765 pH/Temp. Electrode for meats
PH60S-E spear probe for foods (e.g., cheese, sauce, milk, fruits, dough, etc.)
GS2-E spear probe for soil direct test
PH60F-E flat probe for surface test

12. Battery Replacement

Install batteries according to the following steps. Ensure the "+" of every single battery faces UP. WRONG INSTALLATION OF BATTERIES WILL CAUSE DAMAGE! ⚠️

Loosen the pocket clip.
Pull off the battery cap.
Slide and unlock the battery compartment.
Open the battery compartment.
Insert the batteries (all "+" FACE UP).
Press down the battery compartment.
Slide and lock the battery compartment.
Close the battery cap, ensuring it is tightly closed with the O-ring to maintain the waterproof rating.

13. Self-Diagnosis Function

Error Symbol	Self-Diagnosis Information
Er1	The pH calibration solution cannot be recognized by the meter.
Er2	[MEAS] is pressed before measurement is fully stabilized.
Er3	During calibration, readings are unstable for over 3 minutes.
Er4	pH electrode offset out of range (<-60mV or >60mV).
Er5	pH electrode slope out of range (<85% or >110%).
Er6	The calibration reminder is triggered. It's time to perform a new pH calibration.

14. Troubleshooting Guide

Trouble	Reason	How to fix
Calibration Error	Incorrect calibration order (Er1)	Always calibrate pH 7 first, then pH 4 or pH 10. Refer to Section 4.2.1.
	Calibration solutions are in poor condition (Er1)	Ensure calibration standard solutions are fresh, clean, and made by a legitimate manufacturer.
	Contaminated electrode (Er1)	Thoroughly clean the electrode. Refer to Section 6.
	Aged electrode (Er1)	Replace the electrode.
Dried-out electrode (Er1)	Soak in the soaking solution overnight to restore.
Reading is always slowly changing, won't stabilize.	Electrode is not in full contact with solutions (Er1)	Ensure the storage vial is removed and the electrode is fully immersed in the solution (above the junction).
	Air bubbles around the sensor (Er1)	Make a quick stir in the solution to remove air bubbles.
	Pressing [CAL] too fast (Er2)	Wait for the reading to be fully stabilized before pressing [CAL] to finish calibration.
	Contaminated electrode	Thoroughly clean the electrode. Refer to Section 6.
Clogged junction	Refer to Section 6.2 for thorough cleaning of the junction.
Aged electrode	Replace the electrode.
Testing low ionic strength solutions (e.g., distilled water and deionized water)	Refer to Section 5.2.
Display similar readings in any solutions or stuck at 7.00 pH	Broken electrode	If no physical damage is visible and within the 6-month warranty, contact Apera Instruments for warranty fulfillment. If visible damage is present, replace the electrode.
	Instrument defect	Contact Apera Instruments for warranty fulfillment.
Jumping Readings (generating random numbers)	Electrode is not in full contact with solutions	Ensure the storage vial is removed and the electrode is fully immersed in the solution (above the junction).
Jumping Readings (generating random numbers)	Air bubbles around the sensor	Make a quick stir in the solution to remove air bubbles.
Calibration is successful, but I think measurement is not accurate	Electrode is not properly connected or the connector is broken.	Check the electrode's connector; ensure it's not broken and is correctly connected. Refer to Section 11.3. Screw on the connector cap to protect the connector when no electrode is connected.
	Aged electrode	Replace the electrode.
	Air bubbles around the sensor	Make a quick stir in the solution to remove air bubbles.
Wrong buffer standard is selected	Match the buffer standard with the calibration buffers used by changing settings in P1.
Verstopftes Diaphragma [Clogged Diaphragm]	See Section 6.2 for cleaning the diaphragm.
Comparison with other meters, test strips, or drop tests	To compare with other meters, perform a 2-point calibration for all meters using the same standards, then measure a 3rd standard solution. The meter giving a more accurate reading in the 3rd standard is considered more accurate. Test strips or drop tests' accuracy is not comparable to pH meters'.
Calibration solutions are in poor condition	Ensure calibration standard solutions are fresh, clean, and made by a legitimate manufacturer.
The electrode is not suitable for your test sample or testing environment	Contact Apera Instruments to find the most appropriate electrode for your specific application.

15. Appendix

Function Comparison of PH60Z Meter and ZenTest® Mobile App

Functions	PH60Z Meter	ZenTest Mobile App
Display	Basic digital display	1. Basic Mode: digital display + calibration info (with manual data logger available) 2. Dial Mode: see reading change with reading alarm range (with manual data logger available) 3. Graph Mode: see the trend of reading changes (with auto. data logger available) 4. Table Mode: see real-time measurement data by every second (with auto. data logger available)
Calibration	Press buttons to operate	Operate on smartphone following graphic tutorial.
Self-Diagnosis	Er1 – Er6 icons	Detailed problem analysis and solutions.
Parameter Settings	Press buttons to set up (except for P7).	All parameters can be set up in Settings.
Reading Alarm	The screen turns red when alarm triggered; cannot be set up.	Alarm display in all measurement modes, and alarm range can be set up.
Data Management	N/A	Manual or Auto. Datalogger; notes can be added to saved data.
Data Output	N/A	Share data on your smartphone via email or other apps.

16. Warranty

Apera Instruments warrants this instrument to be free from defects in material and workmanship. Apera Instruments (Europe) GmbH agrees to repair or replace, free of charge, any malfunctioned or damaged product attributable to its responsibility for a period of TWO YEARS (SIX MONTHS for the probe) from the delivery date.

This limited warranty does NOT cover damages due to:

Accidental damage, transportation, storage, improper use.
Failure to follow product instructions or perform preventive maintenance.
Unauthorized repair or modifications.
Normal wear and tear.
Other external causes or actions beyond reasonable control.

Contact Information

APERA INSTRUMENTS (Europe) GmbH
Wilhelm-Muthmann-Straße 18
42329 Wuppertal, Germany
Contact: info@aperainst.de
Website: www.aperainst.de
Tel: +49 202 51988998

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