電化學(xué)測量單元和電池倉被設(shè)計在一個整體的固體模塊中,這樣可以延長其使用壽命.測量原理是氧氣減少在陰極，由此產(chǎn)生的電流擴(kuò)散速度，只取決要測量大氣和/或氣體所載氧的濃度成正比.傳感器可以輕松替換，價格不貴。
Oxygen Analyzers
| Electrochemical cells (fuel cells) The electrochemical cell and the measuring chamber are housed in a monoblock construction in order to prevent extended purge times. The oxygen is reduced at the cathode and the resulting current is proportional to the diffusion-rate, which only depends on the concentration by volume of the Oxygen contained in the atmosphere and/or the gases to be measured. The sensor can be easily replaced and is inexpensive. The Oxygen sensors described herein are specific to Oxygen and are capable of measurements below 1 ppb (parts-per-billion) up to and including 100. Oxygen reacts chemically at the sensing electrode fo produce an electrical current signal Output proportional to the Oxygen concentration in the sample gas. The signal Output is linear over all analyzer ranges specified and does remain virtually constant over its normal useful life unlike sensors manufactured by other competitors. Innovative designs, development of proprietary manufacturing techniques, electrodes and electrolyte materials have been combined to optimize the critical characteristics of the Oxygen sensors to produce the first real advancements in sensor technology in decades. Benefits
Paramagnetic Sensor Magnetic properties of gases. All paramagnetic measuring instruments available on the market today are based on utilizing the paramagnetic properties of oxygen. Oxygen is one of very few gases with a strong magnetic susceptibility. The movement of the electrons within a molecule generates magnetic moments. A distinction is made in this context between:
| Principle of measurement: There are various different principles of paramagnetic measurement, though in recent years the magnetomechanical or "dumb-bell" principle has come to be used in most measuring instruments. The principle of measurement is based on a sensor in which a dumb-bell comprising two nitrogen-filled spheres is arranged in rotational symmetry within a magnetic field. The gas to be measured passes through the sensor. If the sample gas contains oxygen, the oxygen is drawn into the magnetic field on account of its paramagnetic properties as described above, thereby strengthening the field. The nitrogen inside the glass spheres has the opposite magnetic polarization and is forced out of the field, causing the dumb-bell to rotate. The degree of rotation is directly proportional to the oxygen concentration. To reduce sensitivity to vibration, the dumb-bell's rotation is no longer measured directly in modern sensors. Instead, a mirror is attached at the dumb-bell's rotational axis and symmetrically reflects a beam of light onto a pair of photocells. When the dumb-bell starts to rotate, a potential difference is generated at the photocells. The resulting current is amplified and conducted around the dumbbell through windings. The current flow generates an electromagnetic countermoment which causes the dumb-bell to return to its original position. The current needed to maintain the dumb-bell in its null position is directly proportional to the oxygen concentration. Benefits
Zirconia-oxygen-sensor Principle of function: The principle of the zirconia oxygen analyzer is as follows: At high temperatures the zinconia element, as a solid electrolyte, is a conductor of oxygen ions. Platinum electrodes are attached to the interior and exterior of the zirconia. Heating the element allows different partical oxygen concentrations of the gasses to come into contact with the opposite side of the zirconia creating an oxygen concentration cell. In other words, oxygen molecules gain electrons to form oxygen ions with higher partical oxygen concentrations. These ions travel through the zirconia element to the other electrode. At that point, electrons are released to form oxygen molecules (refer to the chemical formula). The Nernst expression can be applied to calculate the force by measuring the electromotive force E generated between the two electrodes. Benefits
Housings
|
