What is a Cardioid Microphone?
Cardioid means heat-shaped. Any microphone which has a heated-shaped polar Pattern is called a cardioid microphone. The cardioid is most sensitive to the sounds which arrive from the front. The sounds which arrive from 90 degrees to the side are 6 Decibels less sensitive than to the front, and theoretically, it is completely insensitive to the sounds coming from the rear. In practice, the 100% directional qualities of a cardioid are impossible to achieve due to reflected sounds from walls and ceiling, which are entering the sensitive area of the microphone.
The most important attribute of the cardioid is that the microphone can discriminate between direct sounds and reverberant sounds, which come from all other directions at random. One of the most important uses of the cardioid microphone is in sound reinforcement, where the directivitive allows the system gain to be higher without generating acoustic feedback.
TEXT №3
UNBALANCED AND BALANCED
Most of the mistakes in audio installations are due to incorrect and defective audio connections. In order to perfectly complete your installation, please pay special attention to the following section unless you are already familiar with balanced/unbalanced operations.
WHAT IS AN UNBALANCED LINE?
You can find this kind of system in most of home audio-video systems. They have one conductor to carry signal, and another conductor for a ground. Normally, for lower level signals, the ground conductor shields the signal conductor.
WHAT IS A BALANCED LINE?
A balanced system transmits signal via 2 conductors plus one ground shielding conductor. The 2 signal conductors carry the same signal but out of phase. For the balanced input stage, the amplifier will boost the difference between the 2 signal conductors and remove the identical part (known as common mode signal) of the 2 signals. Because the real signal is carried by the 2 conductors out of phase, so it is perfectly carried to the input. At the same time, interference that occurs during transmission will be identical (common mode). Because the signal conductors are run together, there is no chance they can be different, and all the interference will be removed by the balanced input amplifier.
TEXT №4
ESCO
LABCULTURE CLASS II TYPE A2 BIOHAZARD SAFETY CABINET
SAFETY WARNING
The use of any hazardous material in the cabinet must be monitored by an industrial hygienist, safety officer or some other suitably qualified individual.
|
|
|
Explosive or inflammable substances should never be used in the cabinet unless a qualified safety professional has evaluated the risk involved.
If chemical, radiological or other non-microbiological hazards are being used in the cabinet, additional protective measures should be taken. Besides that, the operation should be monitored by а suitably trained individual
The biohazard symbol (shown alongside) on the front panel of the cabinet indicates the presence of - biological substances that pose а threat to human health.
This cabinet is suitable for agents classified under bio-safety levels 1, 2 and 3. Please refer to Appendix А for more information on bio-safety levels.
For use of bio-safety level 4 agents in the cabinet, the agents should be placed in а negative pressure area.
Please note that while doing so, the operator should be wearing a full body positive pressure isolation suit.
This cabinet should not be used with cytotoxic substances unless it has been determined that the filter can be safely changed.
NB: Cytotoxic substances cannot be inactivated by conventional formaldehyde decontamination
Before you proceed, you should thoroughly understand the installation procedures and take note of the environmental/electrical requirements of the cabinet
In this manual, important safety related points will be marked with this symbol.
If the equipment is used in а manner not specified by this manual, the protection provided by this equipment may be impaired.
LIMITATION OF LIABILITY
The disposal and / or emission of substances used in connection with this cabinet may be governed by various lосаl regulations. Familiarization and compliance with any such regulation are the sole responsibility of the users of the cabinet. Esco's liability is limited with respect to user compliance with such regulations.
European Union Directive on WEEE and RoHS
The European Union has recently issued two directives: Directive 2002/96/ЕС on Waste Electrical and Electronic Equipment (WEEE) and Directive 2002/95/ЕС on Restriction on the use of Hazardous Substances (RoHS).
|
|
|
WEEE: The objective of the WEEE directive is to promote "....the reuse, recycling and other forms of recovery of such wastes (WEEE) so as to reduce the disposal of waste besides improving the environmental performance of а11 operators involved in the life cycle of electrical and electronic equipment, e.g. producers, distributors and consumers...." and hence this directive is relevant to the issue of disposal of this cabinet within the EU. As per this directive, а "wheelie bin" sticker (shown alongside) has to be pasted on all products which come under the purview of this directive, thereby indicating that at the time of disposing the particular product/equipment, it should not be grouped together with general unsorted municipal waste. Instead the directive mandates that distributors of electrical and electronic equipments be responsible for the collection and scrapping of the products they have sold. Please note that this cabinet has been classified as "fixed industrial equipment' and hence does NOT come under the purview of the WEEE directive. At the time of disposing this cabinet, you can still contact your local Esco distributor who would arrange for collection and recycling of this cabinet at а reasonable fee.
RoHS: With respect to the directive on RoHS, please note that this cabinet falls under category 9 (monitoring and control instruments) and is therefore EXEMPTED from requirement to comply with the provisions of this directive.
TEXT №5
Дата добавления: 2018-04-04; просмотров: 296; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!