In 2009, OHAUS expanded Beyond Weighing with our Starter Series: a simple, practical portfolio of water quality analysis meters. By 2015, our Starter Series line had expanded to include pen, portable, and benchtop meters designed to measure everything from pH to dissolved oxygen and conductivity. As our water quality analysis portfolio becomes more sophisticated, we strive to make specialty measurements easier in every laboratory, from the software we equip our meters with down to the electrodes you need for maximum effectiveness in your laboratory.
 
Every Starter Series meter comes outfitted with a standard electrode, but our electrode line is as varied as our selection of meters. At OHAUS, we understand that no two applications are identical; because of that, we've designed these specialty electrodes, made to simplify your measurement process.

OHAUS Product Compatibility
OHAUS' specialty electrodes are compatible with the OHAUS ST300, ST3100, ST3100M, and ST5000. To ensure the most accurate measurements possible, you should always pair them with the STTEMP30 temperature probe.
 
 
ST270
The OHAUS ST270 spear tip electrode is perfect for solid and semi-solid samples, with a conical tip ideal for direct penetration into samples. This makes it easy to get accurate pH measurements of soils, gels, cheese, meats, sauces, dough, or anything that is solid or semi-solid. Constructed with a glass body, the ST270 can resist temperatures up to 100°C and withstand some of the tough chemicals.
 
 
ST260
The OHAUS ST260 is an electrode designed specifically to measure tris buffers. When single junction electrodes are used with tris buffers, an Ag- tris precipitate is formed that clogs the electrode, causing it to fail. The ST260 is a double junction electrode, which isolates the Ag/AgCl reference electrode from the tris buffer by creating a chamber of KCl in the electrode. This KCl chamber separates the tris from the Ag/AgCl electrode to prevent the formation of the Ag-tris precipitate.
 
 
STMicro5 & STMicro8
The OHAUS STMicro5 and STMicro8 are electrodes designed to fit and reach into vessels with a narrow opening or deep basin. Erlenmeyer flasks, graduated cylinders, or test tubes can make measuring pH difficult, because you may not reach far enough into the vessel to completely cover the pH probe, or the electrode may not fit past the bottle's neck. The STMicro5 and STMicro8 are 5/8mm in diameter and 80/150mm in length, respectively, and will reach the bottom of most vessels and get past the narrowest of necks.
 
 
STPure
The OHAUS STPure electrode is designed to measure pure water samples. Pure water has a very low ion concentration, which means that most pH electrodes have a tough time getting a measurement. The STPure has a ground glass junction, which has a very high electrolyte flow rate; this floods the water sample with electrolytes and ions, making it possible to get a fast and accurate measurement.
 
 
STSurf
The OHAUS STSurf electrode is designed with a flat measuring profile. This can measure the pH of the surface of a sample like skin, and paper can be measured. The STSurf can even be used to test spills of unknown agents to determine the best methods to clean it up.
 
 
ST272
The ST272 electrode is the newest addition to the OHAUS electrode roster, and features a glass tip and plastic construction ideal for food processing environments. Built for solid and semi-solid samples, the ST272 provides an optional metal knife-edge blade designed to protect the glass tip while maintaining accurate, repetitive measurements of soft, solid, or even frozen samples.

Learn More about the OHAUS Starter Series