What surveillance cameras look like
The expert told how the devices that measure body temperature are arranged
Some schools do not even need a “pistol” thermometer: a thermal imager under the ceiling scans the temperature of all incoming
In Yekaterinburg, a mother forbade her child to take temperature
In Yekaterinburg, as well as throughout the country, there are parents who refuse to have their children measure the temperature at school. Not so long ago, this led to a scandal at a school in the Southwest, and some mothers managed to ensure that their children did not measure their temperature in a contactless way.
According to active parents, the use of non-contact thermometers can harm the health of children, especially given the fact that they may be subjected to thermometry several times during the same day. Such thermometers, they believe, negatively affect the brain and all body systems in general, especially the organs of vision. And the very shape of the contactless thermometer resembles a pistol. when it is brought to the forehead, it is unpleasant.
Pistol to the forehead. some are unpleasant
Recently, Rospotrebnadzor explained that compulsory thermometry in schools is not a medical intervention, so the parents could not give voluntary consent to this procedure. Body temperature Should be measured in all children in schools and kindergartens, these are the requirements of the new sanitary rules for the duration of the Pandemic.
At the same time, in several Yekaterinburg schools, they installed a new generation of thermal imagers, they look like ordinary surveillance cameras, display a picture on a guard’s monitor and are able to transmit data in a temperature of several dozen students at once.
The device detects heat radiation, but does NOT emit anything itself
We asked an expert. Sergei Dobronravov, head of department at the Yekaterinburg branch of Rostelecom, to explain in a simple way how a non-contact thermometer works and whether it is really worth fearing too frequent thermometry in children.
According to Sergei Dobronravov, thermal imagers do NOT emit, but capture radiation in the infrared range of the spectrum, such devices are considered completely safe. they only collect and analyze thermal radiation data.
New thermal imagers look like this. they are more like a regular camera
In pyrometers, thermometers, “pistols”, the princIPle is the same, only in order to capture the data in body temperature, they need to be brought much closer, the temperature is measured at the moment the button is pressed. In some cases, such devices have beams, they are needed only in order to make it easier to fix the measurement at a certain point, and they are not more harmful than a laser pointer. You can’t shine in the eyes, but the second harm is comments.
According to the expert, distrust of new technologies is a natural reaction, it is quite understandable, but thermometry is the reality of today. Surely in the near future, thermal imagers will appear in public spaces, public institutions; in China, such equIPment is installed in airports and subways, in crowded places.
Read about the rules by which schools now live and how they organized the educational process to comply with them.
It is a compact IP camera with sound for indoor and outdoor surveillance. The device has an IP67 level of protection against external factors, which will effectively protect it under any shooting conditions.
The camera has a 3.6mm lens with an 81 ° field of view. A 1/3 “progressive scan CMOS sensor is used, which is capable of providing shooting with a resolution of 2688×1520.
To perform night surveillance, the device has a built-in IR illumination, which provides a range of camera operation in the evening at a distance of up to 50 m.
The footage can be broadcast online via the Internet or recorded on a memory card. 64GB Micro SD Supported.
This is a wired monofocal outdoor surveillance camera. The body of the device has good protection against external factors. IP67.
The camera has a 2.8mm lens with a 106 ° field of view. 1/3 ” matrix allows daytime shooting with a maximum resolution of 2560×1440.
The camera allows you to broadcast online from the control point, which can be viewed through a web browser.
Up to 20 users can connect to the camera at the same time. You can create a copy of the footage on a memory card with a maximum capacity of 128 GB.
Overview of microphone models
The security systems market offers a large number of different models of microphones for surveillance cameras. They differ in technical characteristics and cost.
Microphone MVK-M022 has a small size and good frequency response. Can be integrated into any electronic device with a 12 V supply voltage.
Main technical characteristics of the microphone:
- Supply voltage. 9-14 V;
- Consumption current. 6 mA;
- The range of reproducible frequencies. 60-7000 Hz;
- Dimensions 43 x 9 x 7 mm;
- Price about 230 rubles.
Microphone Stelberry M50
Compact microphone STELBERRY M-50 is a cylindrical active system with high-speed AGC and sensitivity adjustment.
- Supply voltage. 7.5-16 V;
- Frequency range. 270-4000 Hz;
- Dimensions 52 x 10 mm;
- Acoustic capture zone up to 20 meters;
- Price. 1700 rubles.
The Shorokh 1, 7, 8, 9 family of miniature microphones are active cylindrical microphones for working in conjunction with surveillance cameras.
Technical characteristics of microphones “Shorokh”
- Supply voltage. 5-12 V;
- Frequency band up to 7000 Hz;
- Range up to 7 meters;
- Price. 400-950 rubles.
IP cameras with a built-in microphone have a very developed functionality, but their cost today tends to decrease. So a digital camera Beward BD 3570D costs about 13,000 rubles, and a multifunctional camera RVi-IPC32MS-IR can cost from 6,000 rubles. But if you need high-quality audio from your camera, the best option would be to purchase an inexpensive digital camera and connect a separate microphone to it.
Organization of security systems using equIPment for. and audio recording allows timely identification of threats at the facility and prevent theft, burglary or robbery.
Previously, audio systems were more used to provide two-way communication, but now they are a powerful tool that significantly expands the capabilities of a conventional surveillance camera that is not equIPped with a microphone.
Today, surveillance cameras with sound are widely used in the organization of security systems at the following facilities:
As for the advantage, it is undeniable, since the use of audio recording systems will allow you to get a complete picture of what is happening at the facility, which is controlled.
The disadvantages of cameras with audio recording can be attributed only to their higher cost, the need for additional equIPment and more complex configuration of security systems based on them.
Below we will consider the features of creating this kind of systems, the equIPment used and those additional opportunities that can be obtained from such observation.
Xiaomi Yi Outdoor Smart Camera
This is a fairly inexpensive, but high-quality IP camera with a built-in microphone for outdoor and indoor surveillance of what is happening at the facility.
The camera has a wide viewing angle of 110 °, a focal length of 3.9 mm.
It allows you to broadcast online in Full HD mode or record in the cloud storage.
You can record the broadcast for 30 days, then the saved material will be overwritten.
The devices are distinguished by good protection against the external environment. IP65. They can perform night photography using 12 IR light balls (850 nm). IR illumination is provided up to a distance of 15 meters. Cameras own built-in motion detection system, alarm, APP / PC multi-step viewing.
Varieties of microphones
Microphones used in surveillance systems can be categorized according to the princIPle of operation and design. They can be electrodynamic and capacitor:
- The first type structurally consists of a membrane coupled with an inductor. Under the action of sound waves, the coil is mixed in the field of a permanent magnet and a voltage appears at the ends of the winding. These microphones are not very sensitive, but do not require a supply voltage. The disadvantages of such microphones can also be attributed to a weak signal level, therefore, due to the attenuation of the level, they should be located close to the terminal device.
- Condenser microphones have very small footprint, high sensitivity and wide bandwidth. A subminiature signal amplifier with automatic gain control (AGC) is located in the body of such a microphone, therefore, a supply voltage must be applied to condenser microphones.
IP surveillance cameras with a microphone are a separate group of devices designed to work in computer networks. Most cameras of this type are already equIPped with a built-in microphone, although many users prefer to purchase and connect the microphone themselves.
An outdoor microphone for a surveillance camera is NOT used too often, since external conditions create certain difficulties in the operation of the device. A microphone for outdoor cameras, first of all, must be reliably protected from negative climatic influences. In addition, it is possible to use only directional microphones outdoors due to the large amount of background noise that will be perceived by a microphone with a cardioid directivity pattern.
Surveillance with sound recording with this wired camera can be conducted indoors or outdoors (metal case, protection class IP66, IK08).
The device has a 2.8mm wide-angle lens with a 103 ° field of view.
The camera has a built-in microphone and audio output, there is a slot for installing microSD cards up to 128 GB.
The camera can be rotated 360 ° and rotated within 0 to 75 °. There is a built-in motion sensor and IR illumination for night shooting. The range of her work is about 10 m.
How to organize sound recording in surveillance systems
There are several ways to record an audio track, which will be discussed below.
Connecting a microphone to the camera
Surveillance with sound can also be organized using external microphones that connect to the camera.
These devices are of two types. wired and wireless.
The former predict the laying of cables from the microphone to the camera, and the latter use a radio channel for sound transmission.
From a practical point of view and the quality of the sound obtained, wireless microphones are considered the best option.
They can be placed closer to the controlled object, which will allow you to get a clear and high-quality sound. The presence of various amplifiers and filters in the external microphone will only improve the sound quality of the final audio recording.
Rating of the best surveillance cameras with sound
Consider several surveillance cameras with sound, which are used as part of security systems, providing the ability to obtain a high-quality picture with good sound.
OFFICE SURVEILLANCE CAMERAS
Here is a little material on how to choose a surveillance camera for installation in an office.
The fact is that the conditions of office operation for the equIPment of the surveillance system are very “comfortable”, therefore, many options for cameras planned for installation in the office may simply not be needed, respectively, they will be easier, and most importantly. Cheaper.
Those interested can get acquainted with the characteristics of cameras on this page in more detail, here will also be given some tIPs for their selection.
If the goal is to control the situation during working hours, then such a parameter as sensitivity becomes completely uncritical. Indeed, the illumination, sufficient for the work of employees, all the more “suit” any camera. In addition, the absence of significant changes in the brightness of the lighting in the interior makes it possible to abandon the automatic diaphragm control (ARA).
Installation of cameras in office premises can almost always exclude their exposure, so there is no need to compensate for it.
Thus, the critical characteristics for office equIPment are:
- Angle of view (focal length).
Resolution defines the clarity, respectively, the detail of the image. The main thing here is to observe the measure. If it is necessary to control the actions of employees (visitors), then a resolution of 500 TVL for analog cameras and 720×576 px for IP systems is quite enough.
In any case, striving for high resolution is very often inappropriate, since information recording devices also have a similar characteristic and may simply “NOT keep up” with the camera. In addition, the image quality is determined not only by the matrix, but also, for example, by the lens, so all this must be taken into account.
Next moment. Viewing angle (Focal length) that defines the controlled area. About this in more detail on the page about choosing a camera, here I will say that the larger the angle of view (the focal length is correspondingly smaller), the larger the view area, but the smaller the distant objects look.
Next moment. chromaticity. All other things being equal, the color camera is inferior to the black one. White, sensitivity and resolution, but, since, as already mentioned, this is not critical for the office, it is better to choose color, since it is more informative.
One more question. Use of analog or IP technologies. Each option has its merits and demerits, about it. Office surveillance page.
Last but not least. This is a design. If false ceilings are used in the premises, then the use of dome surveillance cameras will be optimal. They have a good design, the connection and wiring in this case is carried out in the ceiling space, that is, the interior of the premises is not disturbed, the installation of such devices is quite simple.
INSTALLING A SURVEILLANCE CAMERA IN THE OFFICE
Surveillance in the office has several key features, including a moral and ethical component, as well as ways of mounting cameras, choosing their location and organizing recording.
Place to install the camera in the office.
It is not recommended to use surveillance cameras to assess the quality of the work of employees, as this is associated with very strong discomfort that reduces the efficiency of personnel. An exception is the installation of cameras to record work with clients, during which conflict situations may arise.
It is recommended to install the camera in office premises where it is necessary to control the safety of material values, as well as to identify visitors. In the latter case, it is necessary to use equIPment with high technical characteristics, which is associated with additional costs.
Therefore, a combined surveillance system is often used, consisting of SEPARATE cameras for identification and general overview.
Office surveillance systems.
For a large office, IP systems are considered the best option, allowing you to quickly organize full-fledged surveillance with significant savings in the creation of a communication infrastructure. Analog surveillance is recommended for small offices. Relatively cheap and reliable equIPment fully meets the requirements of standard safety systems.
For both of the above options, it is possible to organize remote control of the system, for example, via the Internet, including the creation of archives. However, IP camera-based surveillance has more functionality.
© 2010-2020 G. All rights reserved.
The materials presented on the site are for informational and informational purposes and cannot be used as guiding documents