pH-100
pH-500C
pH-N
Ref-RM
pH tip illustration
pH Redox UniAmp
Designed for research applications within:
Environmental Sciences
Biomedical Sciences
Biotechnology
Microbiology
Food Science

pH Microelectrode

Miniaturized pH electrode

The Unisense pH electrode offers you a fast and reliable research tool. With tip sizes down to 10 µm, you can complete high resolution and non-destructive microprofiles in a wide range of microenvironments. Read more...

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Technical Data
Response Time
Ordering Information & Sizes
Adaptations
Manuals & Videos
pH microelectrode

pH measurement technology

This microelectrode is a miniaturized conventional pH electrode based on selective diffusion of protons through pH glass, and the determination of potentials between the internal electrolyte and a reference electrode. The reference electrode can be either external (separate electrode) or internal. However, we only recommend internal references in applications where it is not possible to place two electrodes in the sample.

pH workshop_1400x800
General
Cables & Connectors
Characteristics
General
Feature Standard Options Extra price for option selection
Feature
Total length
Standard
150-200 mm
Options
70-350 mm
Extra price for option selection
20-50%
Feature
Diameter 20 mm from tip
Standard
<2 mm
Options
<1 mm
Extra price for option selection
10%
Feature
Diameter 50 mm from tip
Standard
8 mm
Options
<2 mm
Extra price for option selection
20%
Feature
Glass shaft diameter
Standard
8 mm
Feature
Plastic shaft protection diameter*
Standard
11 mm
Options
Can be omitted
Extra price for option selection

*When mounted with in situ mini connectors, the shaft has no protection mounted, but fits directly into the in situ sensor mounts with pressure compensation. In situ sensors have a standard length of 130-160 mm.

Cables & Connectors
Item Standard Options Extra price for option selection
Item
Cable
Standard
Habia
Item
Cable length
Standard
1.5-2 m
Options
0-10 m
Extra price for option selection
Yes, depends on length
Item
Connector
Standard
LEMO
Options
BNC adapter
Extra price for option selection
Yes, order separately
Item
In situ gold pin connector*
Standard
No
Options
Yes

*Due to the small area of the pH-sensitive glass, Unisense pH10 electrodes typically have an inner resistance of 10⁹ Ohm. Therefore, the millivoltmeter input resistance must be at least 10¹³ Ohm.

Characteristics
Attribute Standard
Attribute
Guaranteed lifetime
Standard
3 months
Attribute
Expected lifetime
Standard
>6 months
Attribute
Temperature range
Standard
-10-60°C
Attribute
Temperature range tip
Standard
-10-90°C
Attribute
Range
Standard
pH 2-10 (linear 4-9.2)
Attribute
Detection limit
Standard
0.01 pH unit
Attribute
Internal reference
Standard
Only as pH-500C*
Attribute
Spatial resolution
Standard
Approx. 100-250 µm | PH-500: about 500 µm)
Attribute
Response
Standard
Log linear

*Construction of the sensor with an internal reference involves creation of a liquid junction 1 mm from the electrode tip. During measurements, this liquid junction must be submersed in the medium in order to complete the measurement circuit.

Response time
Response time
Response time (90%)
<10 s (from pH 7 to pH 4)
Ordering information & Sizes
Ordering information & Sizes
pH Glass Electrode Size and description Outside tip dimensions (diameter x length of sensitive pH glass)
pH Glass Electrode
pH-10
Size and description
8-12 µm - microelectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
10-19 x 50-100 µm
pH Glass Electrode
pH-25
Size and description
20-30 µm - microelectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
20-30 x 75-125 µm
pH Glass Electrode
pH-50
Size and description
40-60 µm - microelectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
40-60 x 100-200 µm
pH Glass Electrode
pH-100
Size and description
90-110 µm - microelectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
90-110 x 150-250 µm
pH Glass Electrode
pH-200
Size and description
180-220 µm - microelectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
180-220 x 250-350 µm
pH Glass Electrode
pH-500
Size and description
400-600 µm - minielectrode
Outside tip dimensions (diameter x length of sensitive pH glass)
400-600 x 400-800µm
pH Glass Electrode
pH-500C
Size and description
400-600 µm (combination electrode with internal reference electrode)
Outside tip dimensions (diameter x length of sensitive pH glass)
400-600 x 400-800µm
pH Glass Electrode
pH-MR
Size and description
400-600 µm - in guide
Outside tip dimensions (diameter x length of sensitive pH glass)
400-600 x 400-800µm
pH Glass Electrode
pH-N
Size and description
1.1 x 40 mm - needle electrode
pH Glass Electrode
pH-NP
Size and description
1.6 x 40 mm - needle electrode for piercing
pH Glass Electrode
pH-ST-1/4
Size and description
1/4'' steel tube
pH Glass Electrode
pH-SL-1/4
Size and description
FT-cell 1/4'' Swagelok Tee
pH Glass Electrode
pH-SL-1/8
Size and description
FT-cell 1/8'' Swagelok Tee
pH Glass Electrode
pH-PEEK-1/8
Size and description
FT-cell 1/8'' PEEK Tee
pH Glass Electrode
pH-PEEK-1/16
Size and description
FT-cell 1/16'' PEEK Tee
pH Glass Electrode
pH-FT-GLASS-6
Size and description
Glass FT-cell 6 mm outer diameter
pH Glass Electrode
pH-FT-GLASS-8
Size and description
Glass FT-cell 8 mm outer diameter

Video Guides

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Quick Guide pH Microelectrodes

A walk-though of how pH microelectrodes are made, how they work, specifications, and customizations.

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pH Calibration Kit Video

Application Scientist Tage Dalsgaard shows you how to perform a calibration using the pH electrode calibration kit

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