http://www.tradelineinc.com/glossary/index.cfmA: A magnahelic gauge measures air velocity, fan and blower pressures, and filter resistance as well as other things. The gauge shows inches by tenths and so readings are made.

Ещё одно описание:
http://www.bio-blast.com/BVR3600_Manual.pdf

Вот их дом. стр.
http://www.dwyer-inst.com/index.html

дифференциальный манометр (для контроля за перепадом давления, который определяет степень загрязненности фильтра)

Можно добавить:"встроенный в приборы для очистки воздуха"

Он действительно проверяет эффективность работы, например, пылеочистителя, показывая изменения в сопротивлении воздуха, проходящего через фильтр. Судя по описанию, калибровка в дюймах водного столба(непривычно для нас).

http://www.surfacepreparation.ru/xq/asp/g.52/f.26/bf.1/b.12/...
http://www.bio-blast.com/BVR3600_Manual.pdf
SYSTEM DESCRIPTION
The BioBlast® Anilox Roll Cleaning System incorporates the Accustrip System™
Delivery Device and ARMEX® Anilox Roll Formula blast media.
The High Static Vacuum Dust Collection System is designed to recover
ARMEX® blast media from the surface of an Anilox roll while it is being cleaned.
The blast media is discharged through a cyclone into either a 30 or a 55-gallon
drum, thereby optimizing performance and reducing maintenance on the dust
collector.
High Static Vacuum Dust Collection Functions
The High Static Vacuum Dust Collection System operates by utilizing two high
static blowers to collect residual dust and spent ARMEX® into a drum under a
cyclone separator. Fine particles are then sucked into the dust collection vacuum
unit and filtered by the dust collectors filter cartridge. This unit has a “pulse”
function that sends a pulse of compressed air through the filter cartridge to “blow
down” excess dust into the dustbin at the bottom of the unit. The dust collection
vacuum unit can be “pulsed” manually and/or pulsed automatically with the clean
cycle timer.
5
Magnahelic Gauge
The magnahelic gauge located on the dust collector displays the efficiency of the
dust collector by gauging resistance on the air passing through the filter
cartridge. Make sure that the setscrew on the magnahelic gauge is set to zero as
shown in figure 10 below.
A normal magnahelic reading during operation is between 2-8 inches of water. If
the gauge gives a reading of 8 or higher, manually pulse the unit until the gauge
gives a lower reading.
CAUTION: Shut the dust collector down if the magnahelic gauge reads higher
than 8 after manually pulsing the unit.
Manual Clean pulse button
The manual clean pulse button allows the operator to manually pulse the filter
cartridge, thereby blowing excess dust from the filter cartridge into the dust
drawer. When the system is running with a manahelic reading of 8 or higher,
depress the manual clean pulse button for one second and release.
If after manually pulsing, the magnahelic gauge still reads 8 or higher, check both
the main filter cartridge and the inline magnahelic filter. Refer to “changing the
dust collector filter” and “changing the magnahelic inline mini-filter” on page 11.
Figure 10
Set screw
12
MAINTENANCE PROCEEDURES
1. Check the magnahelic gauge
The magnahelic gauge must be checked frequently during operation to
make sure that the dust collector unit is pulsing properly. If the dust
collection unit runs with a magnahelic reading of 8 inches of water or higher,
check the timer pulse rate and duration settings. If there is evidence of
excessive moisture in the system, change the filter cartridge

Мультитран дает просто:
magnahelic gauge дифференциальный манометр (для контроля за перепадом давления, который определяет степень загрязненности фильтра ADENYUR), что в целом совпадает с вышеприведенным описанием оригинала.

Признаюсь в том, что воспользовалась приведенной ссылкой в первом ответе, но прочитала ее и почерпнула эту информацию.