No knobs, no dials, no foul ups
The Model 811 is unlike any pH meter you have ever used. This is an intelligent machine that does everything that a conventional pH meter does - and much, much more - without dials or knobs. It not only gives you digital displays of pH, millivolts, and temperature; but also electrode slope, and time. It lets you standardize at the push of a button because it knows the NBS-assigned pH values of the various buffer solutions at each and every temperature. But what really sets the 811 apart from other pH meters is an uncanny ability to spot and prevent operator mistakes. Here is how the 811 works to make sure that these common pH measurement problems are avoided:
Wrong buffer used. If buffer solution taken from the wrong bottle is used to calibrate a conventional pH meter, the mistake may never be noticed. But with the 811, the operator is immediately alerted to this problem by a warning indicator on the LED display, before erroneous data is recorded.
Wrong buffer value entered. Calibration to a buffer's nominal value when the buffer is not at "room temperature" will cause readings to be inaccurate because buffer pH varies as a function of temperature. For example, a "pH 4.01 buffer"hasapH value of 4.06 at 50°C. The 811 eliminates this problem automatically. A platinum resistance probe gives the microprocessor continuous readings of solution temperature. When the meter is standardized, the correct pH value for the buffer is automatically "looked u p " in memory, locked onto, and displayed.
Incorrect calibration technique. Errors occur when either the operating controls are used in the wrong sequence, or the buffers are introduced in reverse order. The 811 's microprocessor allows the meter to be calibrated on any two buffers in any order.
pH electrode not stable. Incorrect results will be obtained if the operator takes readings before they have completely stabilized. The 811 continuously monitors electrode stability and indicates when readings should be taken.
pH electrode defective. With a conventional pH meter, the operator may be using a defective pH electrode and not be aware of it. The 811 automatically detects and signals poor slope and out-of-spec millivolt values to alert the operator to possible electrode failure.
pH meter defective. It's frequently difficult to tell if a conventional pH meter is operating properly. The 811 has a built-in test mode that lets you verify correct instrument operation at the push of a button. In the unlikely event that the 811 should fail during the first year you own it, we'll take care of the problem with our exclusive "No Lemon" guarantee: We'll replace your meter. Immediately. At no charge. See for yourself this major breakthrough in pH measurement technology. Call now so we can arrange a demonstration in your laboratory.
ORION RESEARCH Call toll-free (except Mass.) 800-225-1480; In Mass. 617-864-5400 Circle 185 for information Circle 186 for demonstration
