EcoSense® pH10 pH/Temperature Pen 

Operations Manual 

YSI pH10 OVERVIEW 

A. Description 

 

 1. Battery cap 

 2. Graphic LCD screen 

 3. Keypad 

 4. Belt clip (Do not remove screw.) 

 4. Electrode collar 

 5. Electrode & ATC assembly – outside o-ring on 

 electrode is yellow and inside o-ring is black. 

 (Electrode cap shown covering electrode.) 

 

 B. YSI pH10 Keypad Layout 

Hold – On/Off key

Store key

Calibration key

Scroll key

INITIAL INSPECTION AND ASSEMBLY 

Carefully unpack the instrument and accessories, and inspect for shipping damages. Notify your 

local dealer or YSI immediately (800-897-4151 or environmental@ysi.com) of any damages or 

missing parts. Save packing materials until satisfactory operation is confirmed. 
BEFORE USING 

A. Insert the Batteries 

1. Remove the battery cap at the top of the unit. 

2. Insert the set of batteries (included) ensuring correct polarities. 

3. Securely replace battery cap. 

B. Soak the Electrode 

1. Remove the electrode cap covering the pH10 meter electrode. 

2. Soak electrode in pH 4 buffer for 10 minutes before first use or after storage. 

OPERATION 

A. Power ON/OFF 

Press “HOLD – On/Off” key for 3 seconds. The unit will turn on and enter the “Measure 

Mode”. Repeat process to turn off. 10 minute automatic shutoff. 

B. Set Date and Time 

1. Press and Hold “CAL” key until it enters “Date/Time Set Mode”. 

2. Press “HOLD” key to select date or time parameters. 

3. Press “STORE” key to increase value or “SCROLL” key to decrease value. 

4. Press “CAL” key for 2 seconds to return to “Measure Mode”. 

C. Select Buffer Set 

1. Press and hold “SCROLL” key until unit enters “Buffer Set Select Mode”. 

2. Press “SCROLL” key again to select either 7.00 (7.00/4.01/10.01) or 6.86 

(6.86/4.00/9.18) buffer sets. 

3. Press “STORE” key for 2 seconds to return to “Measure Mode”. 

Note: This is only needed once unless changing buffer sets. 

D. Calibrate pH 

1. Press “CAL” key for 2 seconds and release to enter “Calibration” mode. 

2. Immerse meter into either pH 7.00 or 6.86 buffer solution depending on which Buffer 

Set you are using. ‘WAIT” will flash. 

3. The pH10 meter will determine when the calibration reading is stable. Meter is 

calibrated when “WAIT” disappears. The unit will automatically enter the next 

calibration point 5 seconds later. One/first point calibration is now completed. Press 

“CAL” key to exit or continue to next step for two/second point calibration. 

4. Repeat Steps 2 and 3 for two/second point calibration by immersing the meter in pH 

4.01/4.00 or 10.01/9.18 buffers. 

5. Move to #6 for three/third point calibration or press “CAL” to exit two point calibration. 

6. Repeat Steps 2 and 3 for three/third point calibration. 

7. When “WAIT” disappears unit will automatically return to “Measure Mode”. 

Note: For accuracy, it is recommended pH calibration is performed routinely with good buffer 

solutions and a clean electrode or anytime after replacing the electrode. 

E. Measure 

Dip the electrode into the test solution while in the “Measure Mode”. 

F. Hold Data 

1. When the pH is stable, press “HOLD” key once to lock the reading on the display. 
2. Press “HOLD” key again to unlock reading and the unit will return to “Measure Mode”. 

The unit is now ready for another measurement. 

Note: The unit cannot be powered off in “Hold Mode”. 

G. Save Data 

Either in the “Hold Mode” or the “Measure Mode”, press “STORE” key for 2 seconds. “DATA 

SAVE” and “M-XX” will appear indicating the reading has been saved and stored in memory 

location XX. The unit automatically returns to “Measure Mode”. 

Note: The non-volatile memory stores up to 50 sets of data (pH, Temperature, Date, Time) even 

if power is lost. If memory is full, the next set of data will overwrite the first data set stored, etc. 

H. Recall Data 

1. In “Measure Mode”, press “SCROLL” key 2 seconds, the most recent set of saved 

data will appear. 

2. Press the “SCROLL” key to view previous saved data. 

3. Press “STORE” key for 2 seconds to return to “Measure Mode”. 

ONGOING MAINTENANCE 

A. Electrode Storage 

1. Electrodes attached to the instrument should be kept in a moist environment. Keep 

the sponge in the chamber moist, tap water is acceptable. The single-junction 

electrode needs to be kept clean; check periodically for cleanliness. 

2. For long-term storage, store in pH 4 buffer. 

ERROR DISPLAYS AND TROUBLESHOOTING 

pH LCD 

Display 

ATC 

Display 

DISPLAY 

 Mode 

Possible cause(s) 

[Action(s)] 

Any Value "OVER" Measure a. Temperature outside 0 to 99.9°C range. 

[Bring solution to a lower/higher temp.] 

b. Bad sensor. [Replace electrode.] 

"OVER" 0.0- 

99.9°C Measure pH value outside 0.00 to14.00 pH range . [Use new buffer, Recalibrate, or Replace electrode.] 

"OVER" 0.0 - 

60.0°C 

pH CAL 

a.pHSTAND 

b.pHSLOPE 

a. Offset @ 7.00pH: mV > 90mV 

Offset @ 6.86pH: mV > 98.3mV 

b. New slope>ideal slope by 30% 

[Use new buffer or Replace electrode.] 

"OVER" 

“UNDER” 

0.0 - 

60.0°C 

pH CAL 

a.pHSTAND 

b.pHSLOPE 

a. Offset @ 7.00pH: mV < -90mV 

Offset @ 6.86pH: mV < -81.7 mV 

b. New Slope < ideal slope by 30% 

[Use new buffer or Replace electrode.] 

SPECIFICATIONS 

Range Resolution Accuracy 

pH 0.00 to 14.00 pH pH 0.01 pH pH ±0.02 pH ± 1 LSD 

Temp. 0.0 to 99.9 °C Temp. 0.1 °C Temp. ±0.3 °C 

Temp. 32.0 to 211.8 °F Temp. 0.2 °F Temp. ±0.6 °F 

pH
Buffer recognition pH 7.00, 4.01, 10.01 or pH 6.86, 4.00, 9.18 

Temperature compensation AUTO 0.0 to 99.9 °C (32.0 to 211.8 °F) 

Buffer temperature range 0.0 to 60.0°C (32.0 to 140 °F) 

Electrode offset ±90 mV at pH 7.00 +98.3 mV / -81.7 mV at pH 6.86 

Electrode slope ±30% at pH 4.00, 4.01, 9.18 and 10.01 

Input impedance >1012Ω

Temperature

Temperature sensor Thermistor, 10 k at 25°C 

General

Battery life Meter: ~35 Hours 

Ambient temperature range 0.0 to 50.0 °C 

Display 98x64 graphic LCD 

Case IP67 water-tight case 

Weight 105 g (3.7 ounces) 

REPLACEMENT PARTS 

Item Number Description 

605112 Instruction Manual 

605113 pH10 Electrode Replacement Kit (Includes electrode, electrode collar, 2 

o-rings, and sensor cap) 

605114 Sensor Cap 

605115 Battery Compartment Kit (Includes battery cover and battery gasket) 

605118 Battery Kit (Includes 4 batteries) 

WARRANTY 

The YSI pH10 Instrument is warranted for one year from date of purchase by the end user against defects in 

materials and workmanship. YSI pH10 electrodes are warranted for six months from date of purchase by the 

end user against defects in material and workmanship. Within the warranty period, YSI will repair or replace, 

at its sole discretion, free of charge, any product that YSI determines to be covered by this warranty. 

To exercise this warranty, write or call your local YSI representative, or contact YSI Customer Service in 

Yellow Springs, Ohio. Send the product and proof of purchase, transportation prepaid, to the Authorized 

Service Center selected by YSI. Repair or replacement will be made and the product returned, transportation 

prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at 

least 90 days from date of repair or replacement. 

Limitation of Warranty

This Warranty does not apply to any YSI product damage or failure caused by: (i) failure to install, operate or 

use the product in accordance with YSI's written instructions; (ii) abuse or misuse of the product; (iii) failure to 

maintain the product in accordance with YSI's written instructions or standard industry procedure; (iv) any 

improper repairs to the product; (v) use by you of defective or improper components or parts in servicing or 

repairing the product; or (vi) modification of the product in any way not expressly authorized by YSI. 

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY WARRANTY OF 

MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. YSI's LIABILITY UNDER THIS WARRANTY IS LIMITED 

TO REPAIR OR REPLACEMENT OF THE PRODUCT, AND THIS SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR 

ANY DEFECTIVE PRODUCT COVERED BY THIS WARRANTY. IN NO EVENT SHALL YSI BE LIABLE FOR ANY SPECIAL, 

INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY DEFECTIVE PRODUCT COVERED BY 

THIS WARRANTY. 

Item #605112 • Drawing #A605112 • Rev B 

• August 2008 • For the latest version of this manual, visit www.ysi.com/environmental

CONTACT INFORMATION

YSI Inc. • 1725 Brannum Lane • Yellow Springs OH, 45387 

800-897-4151 • 937-767-7241 • Fax: 937-767-1058 • Email: ecosense@ysi.com • Website: www.ysi.com