Circa 1950's Excellent condition for collectors of scientific instruments
Gossen are well known German (West originally) makers of light measurement instruments since the 1930's
Most well known for their photographic light measurement accessories but this instrument was produced for the scientific/laboratory community in the measurement of foot candles only.
Readings in foot candles can be taken as Lumens or converted to Lux measurements.
This instrument was previously used by an Australian Federal Government Scientific Organisation
Gossen Foot Candle Meter
Made in Germany around the 1950's - 60's
Model 3.70 549
Complete with the original leather case
Complete with the handheld sensor which plugs into the main unit
Complete with 3x filters for use with the sensor (10x reduction each)
NO instruction manual although using these is pretty intuitive
Having been used only inside for scientific purposes, this instrument is like new - excellent condition.
Meter case appears to be of bakelite (pre plastics), black and not broken or chipped
Meter face measures 72mm x 36mm
Parallax mirror to reduce errors interpreting the readings
Two scales on the meter face, 0 - 10 and 0 - 30 foot candles with divisions down to 0.2 foot candles on the more sensitive scale.
User controls the range with one central switch, selecting either filter or no filter fitted - maximum range selection up to 300 foot candles.
No batteries required, no other adjustments other than the physical meter zero adjustment (usually you do not need to touch this)
Although we don't have the manual, this most likely is a selenium cell based instrument.
The plug in leads to the sensor are approximately one meter long.
The sensor light collecting area is 90mm diameter, the overall diameter of the sensor is 127mm with a comfortable handle grip.
The main handheld sensor body is metal but the handle is likely to be bakelite.
The sensor easily "unlocks" (twist and pull lock) to reveal the inside of the sensor assembly which makes for the filter fitting very easy.
COSMETIC CONDITION:
Excellent condition, almost like it had been received from Gossen 60+ years ago, just a very light leather discolouration where the previous owner had identified the instrument but this old mark is very very light.
Small area in the front of the case, a "pressure mark" where the equipment was packed into the boxes in our storage too tightly - superficial mark only.
The leather case stitching is perfect all round.
Instrument case and accessories all have NO damage to the case whatsoever.
Leads and plugs also in perfect condition.
Spare filters still wrapped in tissue paper.
TESTING:
Not much to say here, except it works! Light measurements (comparative only) showed good smooth response to varying levels.
Probably not calibrated, although I can see no easy way to undertake calibration anyway. I did read that the characteristics of selenium cells could change over time.
Fantastic, fine instrument for the collector of such instruments OR it could still be put into use in areas of light measurement such as:
Work safety environment compliance
Schools and other exam/test areas
Sensitive antiques, museum exhibits, artwork, etc.
Security lighting and night time ATM areas
Computer and clean room standards compliance
Very collectable scientific instrument
