DeFelsko PosiTector SST Mode D'emploi page 7

Step 3: Begin Test (applies to both patch styles)
a) Once the water is injected into either patch, press the
ton to start the test timer.
TIP:
After starting the test timer, the operator can select Power
Off from the Gage menu to conserve battery life. The test timer
will continue to run and the elapsed test time will be displayed
when the Gage is powered-up.
b) Without removing the needle/dispensing tip from the patch,
use the syringe to repeatedly withdraw and inject the water.
ISO 8502-6 recommends this process be completed at least
four times and that the test time be agreed between interested
parties. DeFelsko recommends a test time of two minutes or
longer.
c) After the desired amount of time has elapsed, withdraw the
water from the patch.
d) To complete the measurement, completely fill the PosiTector
SST probe's test cell with the water from the patch. Wait
until the measurement stabilizes (up to 5 seconds), then press
button to save the temperature (T 2 ) and conductivity
the
( 2) of the solution. Δ , the difference between the 2 soluble
salt reading and the 1 background reading, is displayed.
t = test duration
T 2 = sample temperature
Δ = The change in conductivity. The
initial background measurement ( 1 )
is automatically subtracted from the
final measurement ( 2 ). Test results
are displayed in units of
microsiemens per centimeter
(conductivity).
ρ A =The surface density of soluble
salt expressed as sodium chloride.
Test results are displayed in units of
milligrams per square meter, or
micrograms per square centimeter.
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