The meter accepts traditional glass electrodes
and non-glass ISFET technology pH probes.
Compared with salt meters employing glass electrodes
, the ES-421 is easier to use and maintain, and more robust.
Honeywell's latest Durafet III pH electrode is glass-free, so eliminates problems commonly associated with traditional glass electrodes
such as fragility, poor response and frequent replacement.
Two glass electrodes
placed within the posterior and anterior regions of the left ventricle measure the tissue pH and temperature of the heart, sending information via signal wires to a monitor that displays the pH levels.
The probe eliminates problems commonly associated with conventional glass electrodes
such as: frequent probe replacement due to breakage; slow response due to probe aging; frequent calibration; and limited temperature and pH range.
These conducting nanoscale dielectric slivers are what Hunt calls liquid glass electrodes
, fabricated at the U-M Center for Ultrafast Optical Science with a femtosecond laser, which emits light pulses that are only quadrillionths of a second long.
It is packed in a durable Ryton[R] body, resulting in extended life in a wide variety of process conditions, compared with traditional glass electrodes
Due to ISFET technology, it is also claimed to be ten times faster than glass electrodes
For extracellular recording we used pulled glass electrodes
with tip sizes of 3-5 [micro]m and resistances of 3-10 M[omega].
Model 215, a research-grade meter, has dual electrode inputs, allowing both conventional glass electrodes
and solid-state non-glass FET electrodes.
The stainless steel pH probe features a virtually unbreakable sensor that eliminates the frustrations of delicate glass electrodes