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>> This video will demonstrate the process
of using a slicker plate standard,
sometimes called a slicker standard or slicker,
to calibrate a field standard test measure following the
process described in NIST IR7383SOP18.
The slicker plate standard is a calibrated standard having a
known volume, gravimetrically determined between the plain
of the ground top phalange surface
and the upstream face of the drain valve.
These same steps are also applicable to NIST IR7383SOP19.
During the video some process time can be accelerated.
A clock visible in the lower right
of the frame will let you know the actual amount
of the lapsed process time.
Before beginning the calibration we wet down the system
by performing many of the same steps that are used
in the actual calibration but without recording any data,
ensuring that all specified pour
and drain times are observed during the wet down process.
After emptying the slicker plate standard
into the test measure during wet down, allow the water to remain
in the test measure while refilling the slicker plate
standard for the first test measure calibration round.
Do not shortcut the process or measurement errors will occur.
Now I'll demonstrate the wet down process.
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. I've completed the wet down in preparation for carrying
out the calibration procedure.
Next I'll demonstrate the procedure
and at the same time explain each of the nine steps
that make up the process.
As I go I will provide some hints about things to avoid
that can result in measurement errors.
Step one, the slicker plate standard is filled.
As that is done it's best to run the fill tube to the bottom
of the standard to minimize air bubbles in the water.
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The slicker plate standard is filled until the water mounts
up higher than the surface than the slicker plate phalange due
to water surface tension.
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. Step two, measure and record the temperature of the water
from the slicker plate standard.
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Step three, the standard is slicked off.
As the slicker plate slides into position, notice that the edge
of the slicker plate is brought in at a slight down angle
to prevent trapping air under the slicker plate.
Once the plate is covering the top of the standard,
verify that no air is trapped under the slicker plate.
Any trapped air will result in a measurement error.
Step four, now the test measure is emptied following the pour
and drain time specified in this handbook 105-3
for the device being calibrated.
The pour portion of the transfer process will be accelerated
but the onscreen clock will show actual pour time.
Pour the water from the test measure in a controlled
and reasonably constant rate.
For handheld field standard test measures this is a 30 second
pour and 10 second final drain.
Hold hand held test measures at a 10 to 15 degree angle
from vertical for the final drain period.
Then position the empty test measure
under the slicker plate standard drain valve for piping
so no water is lost during the process.
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Step five, the slicker plate is removed while simultaneously
opening the slicker plate standard drain valve.
It is vital that the valve be opened at the exact instant,
or immediately following, the back edge of the slicker plate,
clearing the inner edge of the phalange
so air can enter the standard.
If the valve is open before the edge
of the plate clears the phalange,
any water on the underside of the slicker plate
around the phalange may be drawn into the standard resulting
in a measurement error.
Step six, the slicker plate standard is allowed to empty
until there is cessation of the main water flow.
Then a 30 second count begins.
At exactly 30 seconds the valve is closed
and the slicker plate standard is moved
so that no further drainage into the test measure is possible.
Further drainage will result in measurement error.
[silence] Step seven, verify that the neck
of the test measure is vertical or perpendicular
to a level horizontal plain by placing a level on the side
of the neck as specified in this handbook 105-3.
Do not place it across the top as you might be tempted to do.
In step eight the level of the liquid
in the test measure is read on the site gauge scale
by placing a card with a black half and a white half
to properly indicate the bottom of the meniscus.
Placing the black portion
of the card just below the meniscus causes the bottom
of the meniscus to reflect the black surface
against the white top of the card.
Besides the card, other meniscus reading aids
like the magnifying glass can be helpful.
After taking the reading the value is recorded.
Lastly step nine, measure the temperature of the water
in the test measure and record it.
Note that this measurement is made after reading and recording
and recording the skilled plate reading as water may be removed
by the thermometer during the measurement resulting
in an error.
Then compare the temperature of the water
in the slicker plate standard and the temperature of the water
in the test measure to ensure that the difference is less
than the specified limit as determined by the materials
from which the standard and test measure are made.
If the maximum difference is exceeded the calculations
of SOP19 should be performed or the data discarded
and a new calibration run performed from the beginning.
If the temperature difference is acceptable this data is used
as round one and the entire process is repeated
to gather data for round two.
That's what I'll do now, run the whole process again, nonstop,
with only onscreen text
to introduce each step for round two.
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You have just seen the calibration of a handheld,
field standard, test measure using a slicker plate standard
as the reference.
The calculations to determine the actual proven volume are
detailed in the SOP.
Sample calculations can be downloaded from the website
where this video is provided.
One last note, if there is more than 0.2 cubic inch disagreement
between the scale readings for runs one and run two,
check all vessels for cleanliness,
leaks or other damage, identify and correct any problems.
Such problems must be corrected before an acceptable calibration
can be completed.
Also, as you likely noticed,
we have not addressed the adjustment and sealing
of the test measure for the [inaudible] use.
These topics will be addressed in a future video or podcast.
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