Section 4
Calibration Of Air Flow Sources
With The DigiCal Calibrator
The instructions relate to industrial hygiene air sampling. It, basically,
applies to any gases flow rate measurements.
1. Start the pump and allow approximately 5 minutes to stabilize.
Perform this step before connecting to flow cell as air flow dries
center tube if bubbles are not initiated at intervals.
2. Connect sampling medium to pump by obtaining proper hose
adapters for connecting tubing to flow cell. The flow cell hose
connectors will accept two common sizes of vinyl tubing (1/4" and
5/16"). A "Luer" fitting is incorporated in the upper hose connector.
The upper port is for vacuum and the bottom for pressure. When
the upper port is connected to vacuum, the lower port must be open
to the atmosphere. Conversely, when the lower port is connected to
pressure, the upper port must be open to free air. Never make
bubble test with bottom hose connected in series (in line with
sampling filter).
3. Wet the flow cell as described in Section 3.
4. Begin Calibration:
Depress plunger into cell and quickly release.
Different flow rate can require quicker or slower release of the
button.
5. Carefully observe the bubble passing through the sensor zone. Only
a single straight bubble, perpendicular to the tube wall, is necessary
for an accurate test. If several bubbles go up to the tube at once it
will not effect the test data because the first sensor will not reset
until the final sensor has been tripped. A good technique is to watch
the bubble pass up the tube to ensure a good test has been
conducted.
6. Observe the display. A number will be displayed. The decimal
point will be appropriately placed. Read section 2-b on features
concerning data display.
7. After a 3 second delay from the time the final sensor is tripped
another test can be performed.
8. Repeat Steps 5 through 8 for minimum of 3 tests.
Note : If difficulty is encountered in making a clean single soap film rise
up the center tube :
a. Check level of soap in flow cell (Section 3-C).
b. If soap is cloudy (not clear), change the soap solution and
clean flow cell.
8
c. Battery saver
Another feature of the DigiCal Calibrator is the battery saver
"automatic shut down." If a test is not conducted within
approximately 7 minutes from turn on, the Calibrator will turn itself
off. Continuous use of the batteries is rated at 100 hours. The unit
may also be operated directly from the A/C charger when batteries
are low. All units should be given an initial 16 hour charge prior to
use. A low battery light will indicate when it is time to recharge the
battery. If stored for a period of 30 days or more, unit will require a
16 hour charge prior to operation.
5
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Comments to this Manuals