Customers Also Bought
- Dual Beam Infrared Bijection Range: 100m(outdoor); 300m(indoor)
- Working Voltage: DC 13.8 ~ 24V
- Current: 40mA ~ 65mA
- Operating Temperature: -25℃ ~ 55℃
- Operating Humidity: 5% ~ 95%
- Visibility(RH): ≥5m
- Sensing Speed: 50 ~ 700ms
- Beam: 2 beams
- DSP clip, high alarm technology
- Wired Alarm Detector System and BUS system compatible, holographic spot real-time report
- Self-adaption in environment and trouble locking
- Auto-adjustment transmit power for environment
- Infrared alarm detector has upper and lower optical glasses structure for high precision
- Best Alarm Detector is suitable for both indoor and outdoor use
- Highly accurate lens with double focus
- Low power consumption
- DSP clip, high alarm technology, dual beam infrared variable frequency bijection alarm detector system with LED voltage display
- Wired system and BUS system compatible, holographic spot real-time report
- Upper and lower optical glasses structure for high precision and it is can be easily installed and low power consumption
- In mathematics, a bijection, or a bijective function, is a function f from a set X to a set Y with the property that, for every y in Y, there is exactly one x in X such that f(x) = y. It follows from this definition that no unmapped element exists in either X or Y.
- Alternatively, f is bijective if it is a one-to-one correspondence between those sets; i.e., both one-to-one (injective) and onto (surjective). (One-to-one function means one-to-one correspondence (i.e., bijection) to some authors, but injection to others.)
- For example, consider the function succ, defined from the set of integers to , that to each integer x associates the integer succ(x) = x + 1. For another example, consider the function sumdif that to each pair (x,y) of real numbers associates the pair sumdif(x,y) = (x + y, x - y).
- A bijective function from a set to itself is also called a permutation.
- The set of all bijections from X to Y is denoted as X ↔ Y. (Sometimes this notation is reserved for binary relations, and bijections are denoted by X ⤖ Y instead.) Occasionally, the set of permutations of a single set X may be denoted X!.
- Bijective functions play a fundamental role in many areas of mathematics, for instance in the definition of isomorphism (and related concepts such as homeomorphism and diffeomorphism), permutation group, projective map, and many others
- A smoke detector is a device that detects smoke, typically as an indicator of fire. Commercial, industrial, and mass residential devices issue a signal to a fire alarm system, while household detectors, known as smoke alarms, generally issue a local audible and/or visual alarm from the detector itself
- Smoke detectors are typically housed in a disk-shaped plastic enclosure about 150 millimetres (6 in) in diameter and 25 millimetres (1 in) thick, but the shape can vary by manufacturer or product line. Most smoke detectors work either by optical detection (photoelectric) or by physical process (ionization), while others use both detection methods to increase sensitivity to smoke. Sensitive alarms can be used to detect, and thus deter, smoking in areas where it is banned such as toilets and schools. Smoke detectors in large commercial, industrial, and residential buildings are usually powered by a central fire alarm system, which is powered by the building power with a battery backup. However, in many single family detached and smaller multiple family housings, a smoke alarm is often powered only by a single disposable battery
Carbon monoxide and carbon dioxide detection:
- Some smoke alarms use a carbon dioxide sensor or carbon monoxide sensor in order to detect extremely dangerous products of combustion. However, not all smoke detectors that are advertised with such gas sensors are actually able to warn of poisonous levels of those gases in the absence of a fire
- Performance differences
- Optical or "toast-proof" smoke detectors are generally quicker in detecting particulate (smoke) generated by smoldering (cool, smokey) fires. Ionization smoke detectors are generally quicker in detecting particulate (smoke) generated by flaming (hot) fires
- According to fire tests conformant to EN 54, normally the CO2 cloud from smoke can be detected before particulate
- Obscuration is a unit of measurement that has become the standard definition of smoke detector sensitivity. Obscuration is the effect that smoke has on reducing visibility. Higher concentrations of smoke result in higher obscuration levels, lowering visibility
- 1 x Set of Alarm Detector System
If the order has not been shipped; please contact DinoDirect Live Support for order cancellation.You will get your refund within 24 hours.
If the order has already been shipped; you may return the item to us postmarked within 30 calendar days of delivery. Before that, please contact our Live Support to inform that.
In that case we will refund you the payment excluding actual shipping fees already incurred.
If the item is defective, please contact DinoDirect Live Support and send an email to us at firstname.lastname@example.org attached an image or video file clearly showing the defect of the product. And we will give you a response within 24 hours whether we will resend the item or refund the payment to you for compensation.
For customization, please consider carefully before ordering.Because we do not accept return and replacement.
|Unit Price||USD$ 23.44||USD$ 21.67||USD$ 19.90||USD$ 17.55||USD$ 17.55|
|Enter Wholesale Channel>>|
• If the order has not been shipped; please contact DinoDirect Live Support for order cancellation.You will get your refund within 24 hours.
• If the order has already been shipped; you may return the item to us postmarked within 30 calendar days of delivery. Please contact our Live Support to inform that.
• Please contact Live Chat or click here to learn more return policy.