WTW SenTix Sur PH Surface Electrode with Flat Membrane, Glass Shaft, S7 Connector, 103646
€306.00
% Manufacturer's RRP: €340.00 10% below manufacturer's RRP
- Flat membrane for surface measurements on damp samples
- Glass shaft, 120 mm long, 12 mm in diameter
- Referid polymer filling (lifetime) with annular-gap diaphragm
- Measuring range 2 to 13 pH, temperature range 0 to 50 °C
- Membrane resistance less than 1 GΩ
- S7 plug-in head, connection cable selectable separately
Product information "WTW SenTix Sur PH Surface Electrode with Flat Membrane, Glass Shaft, S7 Connector, 103646"
The WTW SenTix Sur features a flat membrane for surface measurements, for example on gel, bacterial cultures or leather. It is placed on the moist sample and measures the pH value there, without the need to transfer the sample into a container.
Flat membrane and annular gap diaphragm
The sensor is flat in shape; the shaft is made of glass, is 120 mm long and has a diameter of 12 mm. An open annular gap serves as the diaphragm, whilst the reference system (Referid) consists of a polymer filling with a lifetime of service. The electrolyte therefore does not need to be topped up. The membrane resistance is less than 1 GΩ.
Keeping an eye on the measuring range
At 2 to 13 pH, the measuring range is narrower than that of many other SenTix models; the permissible temperature range is 0 to 50 °C. For strongly acidic or strongly alkaline solutions in the vessel, an electrode with a measuring range of 0 to 14 pH, such as the SenTix 20, is the better choice.
Cable and temperature
The S7 connector head is supplied without a connection cable. You can choose between AS/DIN versions with 1 m (order no. 108110) and 3 m (108112), as well as AS/BNC versions with 1 m (108114). A temperature sensor is not fitted. For penetration measurements in semi-solid samples, WTW offers its own model, the SenTix Sp.
Storage and care
The irrigation cap is used for storage. During measurement breaks, the electrode is immersed in reference electrolyte (3 mol/l KCl, Ag⁺-free); overnight, it is placed in the cap filled with this solution. Storing the electrode in a dry place or using deionised water can cause permanent damage to the membrane. The membrane should not rub against the bottom of the container, otherwise it will become scratched. Water containing washing-up liquid dissolves grease and oil; limescale deposits can be removed with citric acid.
Typical applications
- Hair gel, make-up, lotions and creams
- Agar-agar gel and bacterial cultures
- Leather, paper and skin
- Surface measurement on damp samples
Technical details
| Type | pH surface electrode |
| Sensor shape | Flat |
| Shaft material | Glass |
| Shaft length / Shaft diameter | 120 mm / 12 mm |
| Diaphragm | Ring gap (open diaphragm) |
| Reference system | Referid (lifetime polymer filling) |
| pH measurement range | 2 to 13 pH |
| Temperature range | 0 to 50 °C |
| Membrane resistance | < 1 GΩ |
| Temperature sensor | None |
| Connection | S7 plug-in connector, without connection cable |
| Standards | EU Declaration of Conformity (RoHS Directive 2011/65/EU), WEEE marking |
Scope of delivery
- 1 WTW SenTix Sur pH measuring chain with irrigation cap
- Connection cable not included, available separately
Individual requirements and procurement service
Connection cables for the S7 plug-in head, KCl-250 reference electrolyte (order no. 109705) for the rinsing cap and buffer solutions for calibration are available on request via LT Laborhandel. Our procurement service can answer any questions regarding the sample and the appropriate electrode type.