Siemens Schweiz Ag

Siemens Aktiengesellschaft

Aleksandar Duric

Martin Allemann

Martin Forster

Hilmar Konrad

Thomas Bachels

Harald Ebner

Stefan Walker

Mathias Stäger

Erwin Suter

Mathias Stager

The present disclosure relates to smoke detectors. Various embodiments may include a method for adjusting a smoke detector (adjustment method) and a device executing the method for adjusting a smoke detector (adjustment device). For example, a method for automatically adjusting a smoke detector may include: placing the smoke detector in a channel; placing a reference smoke detector into the channel; applying a flowing aerosol to the channel; gathering data from the reference smoke detector reflecting the flowing aerosol; and adjusting the smoke detector based on the data gathered from the reference detector.

Smoke detector methods and systems

An optical smoke detector using a two-color principle is provided. The smoke detector may include a light emitting diode (LED), and a photosensor spectrally coordinated with the LED. The LED includes an LED chip configured to emit light in a first wavelength range, and a light converter configured to convert part of the emitted light from the LED chip into light in a second wavelength range, wherein the second wavelength range has a spectral half-width having a maximum of 150 nm.

Optical smoke detection according to the two-color principle by means of a light emitting diode with an LED chip for light emission and with a light converter for converting part of the emitted light into light of longer wavelength

Various embodiments may include a method for fire detection comprising: radiating light at a first wavelength into a scattered light volume and measuring a radiation intensity generated by forward scattering; radiating light at a second wavelength and measuring a second scattered radiation intensity generated by forward scattering; determining a first quotient from the scattered radiation intensities and comparing it to a first and second value; and if the first quotient lies between the first and the second value; radiating pulses at the second wavelength into and measuring a third intensity generated by backward scattering; determining a second quotient from the first and third scattered radiation intensity and comparing the second quotient with a third value; and generating a fire alarm if the second quotient exceeds the third comparison value.

Fire detection using the scattered light principle with a staggered activation of a further LED unit for radiating in further light pulses with different wavelengths and scattered light angles

An optical smoke detection unit, e.g., for a smoke detector, may include first and second light-emitting diodes for emitting monochromatic, dichromatic or polychromatic light, an optical receiver for smoke detection, and a control unit that controls the light-emitting diodes and evaluates a receive signal output by the optical receiver for fire parameters. The light-emitting diodes may be optically coupled together such that at least one of the light-emitting diodes illuminates the other. The control unit may control one light-emitting diode in an alternating fashion and switch the other light-emitting diode to operate as a photodiode, and simultaneously detect a photoelectric current as a measure of emitted luminous flux of the controlled light-emitting diode. The control unit may deduce and output aging information from the light-emitting diode based on the reduction in the photoelectric current and/or alter the control of the light-emitting diode to correct a corresponding reduction in emitted luminous flux.

Optical smoke detection unit for a smoke detector, with two light-emitting diodes optically coupled together and with an associated control unit for the deduction of aging information and a smoke detector

A method for determining a triggering time for the issuance of an alarm by an alarm device. A measured value is sensed at a measuring time, and the measured value is indicative of a hazard potential within a monitoring range. A waiting time is identified by way of a function which respectively indicates an assigned waiting time for a plurality of different measured values and which has a continuous profile. The triggering time is determined on the basis of the measuring time and the identified waiting time. In addition, an alarm device having a detection device for sensing a measured value and having an evaluation device which is configured to carry out said method is described. In addition, a program element for determining a triggering time for the issuance of an alarm by an alarm device is described, wherein the program element can be loaded into an evaluation unit of the alarm device and can cause the abovementioned method to be carried out.

Determination of an alarm-issuing time of an alarm device

A method and test devices are used for field calibration of gas detectors. Brand new gas detectors are used as measurement standards in field calibration. The brand new gas detectors are in this case either employed directly as working standards, in which case the regular calibration by a reference standard is dispensed with, since the brand new gas detectors are always deemed to be sufficiently accurate. Alternatively, the brand new gas detectors are employed directly, namely as sufficiently accurately calibrated reference standards for the reference gas sensors acting as working standards and incorporated into the test device. In both cases the measured values of the gas sensors in the gas detectors to be calibrated are fed back to a sufficiently calibrated system, namely either directly to at least one brand new gas detector as a working standard or else to a reference sensor of a calibrated test device.

Method and test device for field calibration of a gas detector

An electrolytic gas sensor which is sensitive to a specific gas and has a working, reference and counter electrode is functionally monitored. A differential voltage between the reference and working electrodes is amplified and the potential of the counter electrode is regulated to minimize the differential voltage. Then a measured current flowing into the counter electrode approximately proportionally to the gas concentration of the gas to be detected arises. Independently of the determination of the gas concentration, a working, counter and reference voltage which is present at the three electrodes in each case is captured and monitored for an impermissible deviation. In an impermissible case an assigned error message is then output. Online monitoring of the gas sensor is thus possible and no interruption of the measurement operation for test purposes and additional components are required.

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Zug, Switzerland

Aleksandar Duric