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8.
RH SENSOR CALIBRATION CHECK
The water calibration test verifies that the instrument is working properly. This test only takes a
few minutes. Arizona Instrument recommends that this test be run every day to verify the
system’s calibration and accuracy. For greatest accuracy, each test should be run with new septa.
Ensure the septum is installed with the smooth, shiny, Teflon
®
liner to the inside of the bottle to
prevent moisture from the soft plastic from affecting the result.
Carefully remove a 1.0
µ
l Microcap, AZI P/N 990-0150 from the
storage bottle. Use tweezers to handle the tube.
Just touch the end of the tube into purified or de-
ionized water. The tube must be in contact with
the water long enough to fill, about 10 to 15
seconds. If the tube is not full, the reading will be
low.
Pull the capillary tube straight up out of the water. A rapid but straight motion will tend to
remove excess water from the side of the tube. Excess moisture on the side of the tube will
cause a high reading.
Visually verify that no free water is on the outside of the tube. Wipe the tube only if necessary
with a finger or other non-absorbent instrument. DO NOT WIPE THE TUBE WITH A TISSUE
OR OTHER OBJECT THAT WILL SOAK WATER OUT OF THE CAPILLARY TUBE.
Gently
place the tube into a dry sample bottle just past the bottle’s neck
as shown. Dropping or shaking the tube will cause water to be lost and
will give erratic readings over several tests.
Install a dry cap and septum on the sample bottle with the smooth, shiny
side of the septum to the inside of the bottle.
Gently
place the sample bottle onto the transport so that the tube
rests toward the neck of the bottle as shown.
