The Tris-Compatible Flat pH Sensor is a highly versatile sensor.  Because the glass membrane is flat instead of a bulb, it is more durable, easier to clean, and allows for flat surface measurements or smaller sample sizes.  It features a sealed, gel-filled, double-junction electrode, making it compatible with Tris buffers and solutions containing proteins or sulfides.  The flat glass shape also makes it useful for measuring the pH of semisolids such as food or soil slurries.