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METTLER  »H15«  LAB  SCALE

Mechanical Binary-Coded-Decimal Balance Scale
SN = 125496

EXAMPLE = 123.479 g

HAVE A LOOK INSIDE ...
 ``` ANALYTICAL SCALE M E T T L E R INSTR. CORP., Hightstown, NJ / USA (1960) ************************************************************************** Mechanical Binary-Coded-Decimal Balance Scale, Max = 160 g ; Acc. = .5 mg HOW THE METTLER » H15 « LAB SCALE WORKS : ------------------------------------------- For very low weights the known balance system doesn't work: The mechanical frictions are limitations. The METTLER »H15« use a DIFFERENTIAL METHODE: With NO PROBE in the bowl, the scale is in balance with a CONSTANT WEIGHT of 159.9 GRAM and movable COUNTER-WEIGHT RINGS up to the SUM of 159.9 GRAM The electric wire powers a light bulb. Its light ray projects the (moving) NUMBER-SCALE on the MILKY-SCREEN in front. A PROBE IN THE BOWL brings the scale out of balance. 3 DIGITAL KNOBS (BLACK = 10s; BLUE = 1s; RED = 0.1s) on front LIFT (!!!) the COUNTER-WEIGHTS in the way, until the scale is in balance again: SUM OF L I F T E D COUNTER WEIGHTS = PROBE's WEIGHT. P R I N C I P L E : (A) START Position: ******************* +===============+===============+ 3 x 4 = 12 COUNTER WEIGHT-RINGS | _V_ | are laying on their BASES | ^ | ( TOTAL = 159.9 GRAM ) | | | RED o=o=o=o|o=o=o=o ( .1 + .1 + .2 + .5 ) g | v-v-v-v+v-v-v-v | | | | | BLUE o=o=o=o|o=o=o=o ( 1 + 1 + 2 + 5 ) g | v-v-v-v+v-v-v-v | | | | | BLACK o=o=o=o|o=o=o=o ( 10 + 20 + 40 + 80 ) g | v-v-v-v+v-v-v-v | | | (B) Dials ... | ... L I F T Rings ... +----+----+ ********** +----+----+ ************************* | 159.9g | | | - .1 - .1 - .2 +---------+ | | - 1 - 2 WEIGHT PROBE = | 123.4 g | - 40 - 80 INSIDE +=========+ ^ ... SUM = - 123.4 g DISPLAY = | 12 | 3 |.| 4 | ... made now the left and right side in BALANCE ~ ZERO on Screen ( MILLI GRAMS are to be read on the PROJECTED SCALE / MILKY-SCREEN ) +===============+===============+ (C) ZERO Position: | _V_ | ****************** | ^ | | o=o=o|o=o=o | RED o======|======o ( __ __ __ + .5 ) g | v-v-v-v+v-v-v-v | | | o===o|o===o | BLUE o===o==|==o===o ( __ + 1 __ + 5 ) g | v-v-v-v+v-v-v-v | | | o=o====|====o=o | BLACK . . o=o|o=o . . ( 10 + 20 __ __ ) g | v-v-v-v+v-v-v-v | | | | +----+----+ +----+----+ | 159.9 g | | | +---------+ | | WEIGHT PROBE = | 123.4 g | + WEIGHT-RINGS = 36.5 g INSIDE +=========+ ^ 159.9 GRAM = TOTAL HAVE A LOOK INSIDE ... R E M A R K S T O S E N S I T I V I T Y O F T H E » H 15 « ... ************************************************************************** 2 Marks on the LETTER SCALE represent 1 GRAM [ 1 g ]; 2 Marks on METTLER's »H15« PROJECTION / MILKY SCREEN shows 1 MILLI GRAM. 1 mg = 1/1000 g (!) EXAMPLE: -------- Set all DIGITS to ZERO; the projection screen shows ZERO MILLI GRAM = 0 mg A WHISKER of our cat LEO, placed on the platform, shows a WEIGHT of 3.5 mg H I S T O R I C A L R E M A R K S : ************************************************************************** based on: http://us.mt.com/us/en/home/site_content/aboutus/history.html In 1945, Erhard Mettler, a Swiss engineer, started a precision mechanics company in Kuesnacht, Switzerland. He invented the substitution principle with a single-pan balance, capable of being produced in series. Analytical balances with single weighing pan gradually replaced conventional two-pan balances in the laboratory and »METTLER« became the synonyme for high- precision scales. In 1980 he sold his business to the CIBA-GEIGY AG and in 1989 METTLER acquired TOLEDO SCALE CORP., the largest US manufacturer of industrial and retail scales based in Columbus, Ohio. Its founder, Henry Theobald, had launched an innovative store scale with an automatic weight & price display in 1901. The fusion »METTLER-TOLEDO« was a rational step. impressum: ************************************************************************** © C.HAMANN http://public.BHT-Berlin.de/hamann 08/22/11 ```