What is the working principle of oximeter?
Pulse oximetry is based on two physical principles: (a) the presenceof a pulsatile signal generated by arterial blood, which is relativelyindependent of non-pulsatile arterial blood, venous and capillary blood, andother tissues; and (b) the fact that oxyhemoglobin (O2Hb) andreduced hemoglobin (Hb) have different …
How does an ultrasonic oxygen sensor work?
Ultrasonic Oxygen Sensor Ultrasonic oxygen sensors use sound speed to measure the amount of oxygen in a gas or liquid sample. In liquid, upstream and downstream sensors measure the velocity difference between high-frequency sound waves. The change in velocity is proportional to the amount of oxygen in the sample.
How do optical dissolved oxygen sensors work?
Optical technology developed from the principle that dissolved oxygen quenches the luminescence associated with chemical dyes in the sensor. The probe measures dissolved oxygen by emitting a blue light that causes the sensing element to luminesce or glow red.
Which sensor is used in oximeter?
Pulse oximetry sensors use red and infrared LEDs to measure deoxygenated and oxygenated hemoglobin. LED contamination can affect the oximeter calibration, resulting in inaccurate SpO2 readings below 80%.
What is zirconia probe?
The Probe zirconium dioxide oxygen sensors are available in three lengths. Suitable for aggressive and polluted applications such as boiler exhausts. Longer probes are an ideal solution for thicker walled, insulated flue pipes.
Why mnso4 is used in dissolved oxygen?
Manganese sulfate and potassium hydroxide are added to the sample, forming manganese hydroxide. This reduces the dissolved oxygen, forming a brown precipitate. Alkaline iodide-azide reagent is added to correct for the presence of nitrates found in wastewater samples that can interfere with the oxidation procedure.
How does an optical DO sensor work?
Optical DO sensors measure the DO concentration of liquid media or air based on the quenching of luminescence in the presence of oxygen. Since oxygen affects both the intensity and the lifetime of the luminescence, either may be used to measure DO.
How is SpO2 calculated?
Another way for calculating SpO2 is taking the AC component of only the signal and determinate ratio by using following equation. SpO2 is the value of RX100. Equation 2: Iac = Light intensity at 1 (660 nm) or 2 (940 nm), where only the AC level is present.
What is the range of SpO2?
A normal level of oxygen is usually 95% or higher. Some people with chronic lung disease or sleep apnea can have normal levels around 90%. The “SpO2” reading on a pulse oximeter shows the percentage of oxygen in someone’s blood. If your home SpO2 reading is lower than 95%, call your health care provider.
How many LED are used in pulse oximeter probe?
The pulse oximeter needs two different wavelengths to perform measurements. These wavelengths are generated using two Light Emitter Diodes (LEDs), a Red LED (660 nm,) and an Infra Red LED (940 nm).
What is the wavelength of infrared LED in pulse oximetry?
940 nm
The oximeter utilizes an electronic processor and a pair of small light-emitting diodes (LEDs) facing a photodiode through a translucent part of the patient’s body, usually a fingertip or an earlobe. One LED is red, with wavelength of 660 nm, and the other is infrared with a wavelength of 940 nm.
What is the uses of zirconium?
It is used to make crucibles that will withstand heat-shock, furnace linings, foundry bricks, abrasives and by the glass and ceramics industries. It is so strong that even scissors and knives can be made from it. It is also used in cosmetics, antiperspirants, food packaging and to make microwave filters.
What is zirconia cell?
The zirconia cell is a high temperature ceramic sensor. It is an electrochemical galvanic cell comprising of two electrically conducting, chemically inert, electrodes attached to either side of a solid electrolyte tube.
What is a zirconia cell?
What is the working principle of led?
Working Principle of LED The LED stands for light-emitting diode and in the below figure, you can see the symbol of LED. The working of LED is very simple when led is in forward biasing conditions the electrons existing in N side of diode cross the PN junction and enter in the P region combine with the holes existing in that region and emit light.
What is the working principle of the light emitting diode?
The working principle of the Light emitting diode is based on the quantum theory. The quantum theory says that when the electron comes down from the higher energy level to the lower energy level then, the energy emits from the photon. The photon energy is equal to the energy gap between these two energy levels.
How is the energy transferred in LED light?
The designing of the diode can be done with a semiconductor material & the flow of electrons in this material can give their energy the heat form. The LED is designed with the gallium phosphide & gallium arsenide whose electrons can generate light while transmitting the energy. It has a low-reverse breakdown voltage.
How does a p-type diode work?
The P-type silicon is in the blue color and it contains holes, they are indicated by the white circles. The power supply across the p-n junction makes the diode forward biased and pushing the electrons from n-type to p-type. Pushing the holes in the opposite direction. Electron and holes at the junction are combined.