Classifications

• • G—PHYSICS
  • G08—SIGNALLING
  • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
  • G08B17/00—Fire alarms; Alarms responsive to explosion
  • G08B17/10—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
  • G08B17/11—Actuation by presence of smoke or gases, e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means using an ionisation chamber for detecting smoke or gas
  • G08B17/113—Constructional details

Definitions

• the present invention relates to an improvement in an ionization type smoke detector of a source type.
• ionization type smoke detectors radiation sources are separately supplied to the external ion room for measurement where smoke flows in and the internal ion room for comparison where smoke does not flow.
• a small hole is provided in the intermediate electrode that separates both ion chambers, and the radiation source provided in the internal ion chamber through this hole allows the external ion source to be used. It was also known to irradiate the room / source system.
• the source type has a simple structure and requires less radiation source than the two-source type, but it actually smokes. When an operation test is performed by adding a sensor to the sensor, smoke is prevented from flowing into the internal ion chamber through a small hole.
• the external ion chamber was also difficult to remove once smoke had entered, and the sensor did not recover as soon as the test was completed.
• the hole of the intermediate electrode is enlarged, and the resistance value of the ion chamber does not change even if smoke flows into the internal ion chamber.
• the ion current in the internal ion chamber was re-used in the region where the saturated ion current flows, but the radiation source was constantly exposed to the atmosphere, and the radiation source was polluted and the internal and external IOs were damaged.
• OMPI v May have resulted in cropping or unreporting.
• the present invention does not contaminate the radiation source, and when the test is actually added for operation tests, the smoke is quickly diffused after the test is completed, and the operation is restored. It provides a source-type ionized smoke detector.
• / is the substrate on which the electrical circuit is provided
• ⁇ 2 is the ring-shaped wall provided on the lower surface of the substrate /
• the screw is used.
• ?? is provided on the electrode ⁇ that can be adjusted up and down.
• ⁇ is a disk-shaped inner electrode placed on the ring wall J
• 7 is a small hole provided at the center of the electrode ⁇
• ⁇ is a plurality of columns parallel to the inner electrode ⁇ .
• a disk-shaped intermediate electrode supported, / is a hole provided in the center of the electrode, and / / is a wire mesh external electrode attached to the substrate / so as to cover the electrodes ⁇ and ⁇ ⁇ .
• an external ion chamber ⁇ is formed between the intermediate electrode and the external electrode //, and the radiation of the radiation source J is coaxial with the radiation source J. It is radiated to the rooms a and ⁇ through the provided mosquitoes 7 and / 0, and is arranged to ionize the air inside.
• the internal pepper ⁇ is connected to the positive terminal P of the sensor, the external electrode // is connected to the negative terminal ⁇ of the sensor, and the intermediate electrode is connected between the positive and negative terminals P and II via a resistor R.
• the electrode is connected to the positive and negative terminals " ⁇ ; ⁇ ".
• the source is connected to the switching circuit connected between the positive and negative terminals P and n.
• a voltage is applied to the inner ion chamber a so that a saturated ion current flows.
• the inner and outer ion chambers a and b of the detector have multiple tortoises as pillars?
• the air containing dust flows into or out of the ion chambers a and ID according to the flow of air in the room.
• the radiation source J has a small hole 7 in the internal electrode, but because it is almost covered with this electrode ⁇ and the rig wall ⁇ 2, there is no air flow inside. It is kept in a beautiful state.
• the ion current in the external ion chamber ⁇ decreases, and the gate potential of the FET rises and the switch reaches a predetermined potential.
• the ringing circuit operates and reports a fire.
• Test 3 ⁇ 4 When smoke is actually added to the sensor by the smoke tester, the test is terminated and the smoke tester is moved away from the sensor. The smoke that has flowed into the room is in a state in which air flows freely in the room a, so that it is quickly diffused and restored in accordance with the flow of air flowing through the room.
• a radiation source J was provided.
• the potential of the electrode is changed by a variable resistor, the potential of the intermediate electrode changes relatively, and the sensitivity of the sensor can be changed.
• the ionization type smoke detector of the present invention is configured and operated as described above, the radiation source is not easily polluted.
• FIG. 3 is a cross-sectional view of one embodiment of the ionization type sensor according to the present invention
• FIG. 3 is a circuit diagram of FIG. a ⁇ 'Internal ion chamber, ⁇ ' External ion chamber, 7 ⁇ -Substrate, 1 '' Ring wall, J ⁇ 'Radiation source, internal electrode, 7, / 0 ⁇ ' Mosquito, S-'Middle electrode, II' 'External electrode.

Landscapes

• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fire-Detection Mechanisms (AREA)
• Other Investigation Or Analysis Of Materials By Electrical Means (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=13804477

Family Applications (1)

Country Status (5)

Families Citing this family (7)

Citations (1)

Family Cites Families (7)

• 1982
  • 1982-06-07 JP JP1982083510U patent/JPS58186463U/ja active Granted
• 1983
  • 1983-06-07 WO PCT/JP1983/000187 patent/WO1983004449A1/ja not_active Ceased
  • 1983-06-07 US US06/573,923 patent/US4594512A/en not_active Expired - Lifetime
  • 1983-06-07 EP EP83901734A patent/EP0111012B1/de not_active Expired
  • 1983-06-07 DE DE8383901734T patent/DE3380374D1/de not_active Expired

Patent Citations (1)

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