User Guide
29
Slower response than specied.
M or V Series meters feature an RS-232 programmable Geometric Running Average (GRA). Depending
on the full scale range of the meter, it may have the GRA set to enhance the stability/readability of
the display, which would result in slower perceived response time. If you require the fastest possible
response time, please consult the factory for written instructions on adjusting the GRA.
Jumps to zero at low ow.
M or V Series meters feature an RS-232 programmable zero deadband. The factory setting is usually
0.5% of full scale. This can be adjusted via RS-232 programming between NONE and 6.375% of full
scale. Contact the factory for more information.
Discrepancies between old and new units.
Please see “Standard Gas Data Tables” explanation on page 24.
Maintenance and Recalibration
General: M or V Series Flow Meters require minimal maintenance. They have no moving parts. The
single most important thing that affects the life and accuracy of these devices is the quality of the gas
being measured. The meter is designed to measure CLEAN, DRY, NON-CORROSIVE gases. A 20
micron lter (50 micron for 50 LPM and up) mounted upstream of the meter is highly recommended.
Moisture, oil, and other contaminants can affect the laminar ow elements and/or reduce the area that
is used to calculate the ow rate. This directly affects the accuracy.
Recalibration: The recommended period for recalibration is once every year. Providing that the CLEAN,
DRY, and NON-CORROSIVE mantra is observed, this periodic recalibration is sufcient. A label located
on the back of the meter lists the recalibration due date. The meter should be returned to the factory for
recalibration near the listed due date. Before calling to schedule a recalibration, please note the serial
number on the back of the meter. The Serial Number, Model Number, and Date of Manufacture are also
available on the Manufacture Data 2 screen (page 14).
Cleaning: M or V Series Flow Meters require no periodic cleaning. If necessary, the outside of the meter
can be cleaned with a soft dry rag. Avoid excess moisture or solvents.
For repairs, recalibrations, or recycling of this product contact:
Apex Vacuum
222 Riverstone Drive
Canton, GA 30114
USA
Ph. 404-474-3115
Website: www.apexvacuum.com
Warranty
This product is warranted to the original purchaser for a period of one year from the date of purchase
to be free of defects in material or workmanship. Under this warranty the product will be repaired or
replaced at manufacturer’s option, without charge for parts or labor when the product is carried or
shipped prepaid to the factory together with proof of purchase. This warranty does not apply to cosmetic
items, nor to products that are damaged, defaced or otherwise misused or subjected to abnormal use.
See “Application” under the Installation section. Where consistent with state law, the manufacturer shall
not be liable for consequential economic, property, or personal injury damages. The manufacturer does
not warrant or assume responsibility for the use of its products in life support applications or systems.