Light barrier

This issue has been addressed by the second type of aseptic filling system in which a polyethylene bottle (which can be multi-layered to add a gas or light barrier) is moulded under sterile conditions. While the bottle is still sterile, and the polyethylene is soft, the trim material above the neck finish (moil) is crimped closed to seal the bottle. The sealed, sterile, empty bottle can then be packed and transported to a filling line, which may be in another location from... 

Because of their conductivity, reflecting effect, and light barrier properties, metallized films are increasingly used as functional coatings in technical applications. Examples include battery cell cases, prepaid telephone cards, self-adhesive labels, insulation foil in the building industry, decorative foil for design elements, security features for bank notes, and tear tapes, etc. 

Rysstad, G., Ebbesen, A., and Eggestad, J. (1998). Sensory and chemical quality of UHT-milk stored in paperboard cartons with different oxygen and light barriers. Food Addit. Contain. 15,112-122. 

Figure 6.183 One-way light barrier (transmitter/receiver separated).

Figure 6.184 Reflection light barrier (transmitter/receiver integrated, folded optical path).

DR within 10 mM Tween 20 solution was UV-irradiated under 253.7 nm indicates that lower acetone concentration (less than 2 mol/L) has a positive effect. High concentration of acetone, oppositely acts as a light barrier to slow down the photodegradation rate. 

This sensor principle is digital as the code track shuts the light in front of the receiver on and off. It is a quadrature encoded type as the two light barriers are at 90°. A mask is placed in front of the photosensors. Both code track size and mask slit size have to mate with each other to give a high-precision output signal. An example for this kind of sensor configuration (used in an SAS for ESP) can be seen in Fig. 7.11.6. 

In contrast to the sensor principle described above, there is a solution that uses a Gray code encoding technique in combination with several light barriers, as shown in Fig. 7.11.8. The upper rotating disc carries teeth and gaps encoded as a 6-bit Gray code. All transmitter and receiver elements are assembled in the stator, which forms a set of optical barriers [15]. 

The fundamental principle of CO2 IR sensors is based on a light barrier . Figure 23-16 shows the fundamental method of CO2 and N2O measurement. 

Figure 23-19 a shows the fundamental structure of the light barrier with a pulsed light source to be used in the case of simple interface electronics such as a lock-in-amplifier. The filter for the spectral dispersion is placed in a parallel light beam. The band pass filter for the 4.26 pm region can consist of two components. The one-channel method either works without periodic automatic calibration or calibrates on C02-free inspiration gas as, eg, during normal ventilation in intensive care. Zero-point calibration uses gas blends without CO2. Full-scale or span calibration is carried out by use of specific test gas blends. 

Fig. 4. Setup for the acquisition of (a) reflectance, (b) transmittance, and (c) interactance spectra, with (i) the light source, (ii) fruit, (iii) monochromator/detector, (iv) light barrier, and (v) support. In interactance mode, light due to specular reflection is physically prevented from entering the monochromator by means of a light barrier (Nicolai et al., 2007).

The service station comes with one complete mould carrier on its freestanding frame. It is equipped with a dedicated thermoregulator for warming of moulds destined to be inserted on the moulding line, along with all the required safety fences/light barriers, controls, and connections for air, water and electrical power. 

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