The magnetic field strength threshold alarm is responsive to the magnetic field strength responsive to the magnetic field strength, operated in response to the magnetic field strength exceeding a predetermined threshold value, and is operably configured to operate without consuming energy and output an alarm in response to the operation of the sensing means, and the detection hand An alarm means is configured to prevent energy from being consumed prior to the stage operation and consumes energy only after operation of the sensing means. Therefore, energy is not consumed by alarm means before operation. This alarm may be equipped with energy storage means for supplying electrical energy, and the detection means, the warning means, and the energy storage means are supplied with energy from the energy storage means only when the sensing means is operated Operatively connected.磁場強度閾値警報器は,磁場に反応し,所定の閾値を超える磁場強度に応答して作動し,エネルギーを消費することなく作動するように動作可能に構成された検知手段と,検知手段の作動に反応して警報を出力し,検知手段の作動より前にエネルギーを消費しないように構成され,検知手段の作動の後にのみエネルギーを消費する警報手段とを備える。したがって,作動の前に警報手段によってエネルギーは消費されない。この警報器は,電気エネルギーを供給するエネルギー貯蔵手段を備えていてもよく,検知手段と,警報手段と,エネルギー貯蔵手段とは,検知手段が作動した時にのみエネルギー貯蔵手段から電気エネルギーが供給されるように動作可能に接続される。
