Hach HIAC PODS GLYCOUNT Manuel D'utilisation De Base page 13

Sample inaccuracies result from excessive air bubbles and water
contamination. Both are counted as particles. To remove the air bubbles,
apply a vacuum to the sample in a vacuum chamber or put the sample in
an ultrasonic bath for several seconds.
Particles settle to the bottom of a sample bottle within minutes, so a
sample should be shaken to re-suspend the particles and degassed to
remove bubbles.
Highly contaminated samples soak the sensor and make the particle-
count data invalid. The instrument limit is 20,000 particles per ml at 5%
coincidence loss (per ISO11171) and 30,000 particles per ml at 10%
coincidence loss of fluid for a specific size. If contamination is seen
suspended in a fluid sample, the sample contains concentrations beyond
the saturation limits of the instrument. The average person only sees
particles greater than 40 μm in size.
Use the fluid sampling vacuum pump to take sample fluid from
reservoirs.
1. Cut a length of clean tube that extends from the fluid in the reservoir
to a point accessible from outside the reservoir.
2. Connect a clean sample bottle to the fluid sampling vacuum pump
(VP633001). Install one end of the tube to the pump so that it
extends into the sample bottle and tighten the knob.
3. Install the other end of the tube into the reservoir. Do not
contaminate the end of the tube.
4. Use the pump to fill the sample bottle to the applicable level.
5. Disconnect the sample bottle from the pump.
6. Install the cap until the sample is ready to test.
Prepare to take an online measurement
Suitable places for an online measurement include:
• Upstream of the high pressure filter (condition after pump)
• Upstream of the return filter (condition after system)
• Upstream of the bypass filter (tank condition)
1. Disconnect the hydraulic hose that connects the instrument to the
system to be tested.
2. Remove the previously tested fluid.
3. Set the purge volume to two times the internal volume of the
hydraulic hose.
4. Speak to an application specialist before the port installation.
Note: Do not install any additional fluid control devices on the hydraulic sample
hose or the system test port. These devices make bubbles and create particle
traps that cause sample inaccuracies.
Flush the instrument in bottle mode
Note: If the flushed volume exceeds the amount of fluid in the bottle adapter,
pneumatic pressure is flushed through the instrument and out of the drain port.
This creates air pockets in the hydraulic system and leads to sampling errors.
1. Make sure that a CO bottle or shop air is connected to the
2
instrument and that the pressure gauge shows 90 to 110 psi (6.2 to
7.6 bar).
2. Turn the bottle adapter counterclockwise to disconnect the adapter
from the instrument.
3. Fill a sample bottle with the fluid to be flushed.
4. Put the sample bottle into the bottle adapter and connect it to the
instrument.
5. From the main menu, push F4 to go to the flush menu.
6. Push START.
7. Push F1 (SOL ON). The bottle adapter pressurizes and fluid begins
to exit the drain port. The amount of fluid that is flushed is shown on
the display.
8. When the fluid has been flushed, push CANCEL to stop the fluid and
return to the main menu.
Flush the instrument in the online mode
1. Connect the online adapter to the instrument. Move the pick-up tube
into the hole in the center of the adapter and turn the adapter
clockwise until the pick-up tube is locked.
2. Connect a hydraulic hose with a Minimess
online adapter.
®
test hose thread to the
English 13