|CHECK THE SCALE WEIGHING
All scales have a maximum weighing and accuracy capability.
Scales are sold accordingly and are priced on how accurately and
over what range they can weigh.
Sample and production colours are usually weighed
in the region of 100g - 200g and 1 - 2 kg respectively. The scale
must be able to register in at least 0,1g increments up to 2 plus
The most useful scale in a colour kitchen that is
not too costly is one that measures up to 3 kilograms in 0.1 g increments.
The increments that a scale reads or registers are also seen as
the permitted deviation or error of the scale. So if the scales
accuracy is 0.1g then the acceptable deviation when measuring a
1-kg test weight must only be 0.1g, i.e. the scale could read between
999.9 g and 1000.1 g.
Obviously a scale that registers in 0.5 g increments
would have a much larger window of latitude - between 999.5 g and
1000.5 g. One could have a scale that measures smaller quantities
accurately up to 1.5kgs and another scale to weigh the larger bulk
quantities such as 10kgs.
CHECK THE ACCURACY OF THE SCALE
All good scales have a weighing area or pan that should
give you the same weight irrespective of where the weight is applied
to the pan. If a 1 kilogram weight is placed in the middle or the
corners of the weighing pan, the scales should give the same reading.
If the reading differs depending where the weight
is placed, then the scale will not record any additions accurately
i.e. a differing weight would be shown depending on where the additions
are made to the bucket of ink (front, side or middle). One must
be able to place additions anywhere in the bucket and still be able
to achieve the same accurate reading.
If the deviation is consistently larger than the permittedincrement
accuracy of the scale, then it needs servicing and re-calibration
by a technician. For example, if the difference in the weight of
the 1kg test weight placed in the center or the edges of the weighing
pan gives a weight of 999.5g for a 0.1g scale accuracy, the scale
is then out by 0.4g consistently and must be re-calibrated.
CHECK THE SCALES ELECTRONIC TRACKING PROGRAM
All electronic scales are programmed to be able to
tolerate and not register a small amount of vibration and wind disturbance.
This is called the tracking ability of the scale. The more expensive
scales can be programmed to accept various degrees of vibration
or wind disturbances depending on the environment that they are
in. The less expensive scales have a set standard and crude
This tracking mode is operative when the scale is
in zero or re-zeroed and accommodates small amounts of drafts or
vibrations; it does not see the influence of these small
disturbances to the pan balance. Some scales see minute
additions of colour as wind and/or vibration disturbances and the
scale subtracts or tracks out this small actual weight i.e. it zeros
the scale again even though you have put a little bit of ink onto
The scale will continue to do this, i.e. show a zero
value, when in fact you have added an amount in excess of the increment
registration value of your scale. This type of faulty
or crude tracking program can play havoc with trying to add and
record touch colours. As soon as the scale feels a definite
positive weight, it changes over to the weighing mode and will register
any, even minute additions of weight to the pan. This is obviously
a good thing in an industrial workshop or printshop but it can have
disastrous implications for the colourist in that some scales have
the tendency to not see small sequential additions of
It is therefore very important to see if your scale
tracks out small quantities of pigment addition in order to determine
if your scale is suitable for measuring small sequential additions
||Firstly, your scale must be placed
on a firm, solid counter top that does not pick up vibrations
easily and is out of the way of any drafts. If the work surface
is shared, then someone just leaning against or on the counter
could effect the reading on the scale.
||Drafts and people walking past the
scale can produce fluctuations and inaccuracies in weighing.
If drafts are a problem then erect barriers around your scale
to stop the fluctuations in weight.
||The next most essential detail to
attend to before checking out the tracking mode is to ensure
that the scale is leveled. If the scale is tilted to one side,
the bottom of the scale will register more weight
than the top of the scale. This is similar to the
situation where a heavy object is carried up stairs and the
person at the bottom bears most of the weight compared to the
person carrying at the top.