Kyokko Longwave Infrared Petcare Lamp

This lamp appears to be unique to the Japanese market, for which it was produced by the small manufacturer Kyokko Electric Industrial Co. Ltd, a division of Asahi Kodenki Kogyo Co. Ltd. (Asahi Photoelectric Machinery Co. Ltd.). It is a low power source of heat for keeping plants and small animals warm, such as pictured on the side of its packaging.

The filament is believed to be made from Nichrome wire, consisting of a nickel-chromium alloy. When first heated the chromium forms a protective oxide sheath over the surface, which greatly extends life by preventing oxidation at up to 1400K. It is possible that the filament may alternatively be wound from Kanthal wire, which can be used up to around 2100K. That alloy consists mainly of iron with additions of chromium (20–30%) and aluminium (4–7.5%). The aluminium forms an additional protective oxide sheath allowing still longer life while also increasing resistivity and allowing shorter wire lengths for a given power.

The filament is supported by a ceramic disc through which it passes in a snake-like fashion, its ends being further held in place by a pair of mica discs which are supported on a metal tube in contact with the glass stem assembly. When energised the filament reaches a dull red heat estimated to be around 1000K, and the ceramic former is also heated up and contributes to the infrared radiation. The whole assembly is sealed into a mushroom-shaped glass bulb, which is protected by a clear silicone coating over its outer surface to retain the fragments in case the glass should be accidentally broken during use. Due to the low filament temperature, it warms its environment mainly by convection rather than direct radiation as with other infrared lamps.

Manufacturer:	Kyokko Denki
Lamp Power:	40 Watts
Lamp Voltage:	100 Volts
Lamp Current:	0.4 Amperes
Cap Type:	E26s/25	Brass + vitrite
Bulb Type:	M-75	M-23.5 in eighths/inch
Bulb Finish:	Shatterproof silicone	Clear soda-lime glass
Filament Type:	C-17	Kanthal wire
Atmosphere:	Air
Luminous Flux:	Approx 1 lumen
Luminous Efficacy:	N/A
Luminous Intensity:	N/A
Beam Distribution:	N/A
Colour Temperature & CRI:	CCT: 1000K	Ra: N/A
Chromaticity Co-ordinates:	CCx: N/A	CCy: N/A
Lifetime:	Indefinite
Burning Position:	Universal
Overall Length:	115 mm	4½ inches
Light Centre Length:	75mm	3 inches
Factory:	Kita-ku, Tokyo	Japan
Date of Manufacture:	2000 Approx.
Original Value:	JP¥ 700


References:	1) Photoelectric measurement.
	2) Optical Pyrometry of filament.