Series 2000 Magnehelic® Differential Pressure Gage
Indicate Positive, Negative or Differential, Accurate within 2%
Select the Magnehelic® gage for high accuracy--guaranteed within 2% of full scale--and for the wide choice of 81 models available to suit your needs precisely. Using Dwyer's simple, frictionless Magnehelic® gage movement, it quickly indicates low air or non-corrosive gas pressures--either positive, negative (vacuum) or differential. The design resists shock, vibration and over-pressures. No manometer fluid to evaporate, freeze or cause toxic or leveling problems. It's inexpensive, too.
The Magnehelic® gage is the industry standard to measure fan and blower pressures, filter resistance, air velocity, furnace draft, pressure drop across orifice plates, liquid levels with bubbler systems and pressures in fluid amplifier or fluidic systems. It also checks gas-air ratio controls and automatic valves, and monitors blood and respiratory pressures in medical care equipment.
Note: May be used with Hydrogen. Order a Buna-N diaphragm. Pressures must be less than 35 psi.
Please see SERIES AT22000 for ATEX approved.
- Filter Monitoring
- Air Velocity with Dwyer Pitot Tube
- Blower Vacuum Monitoring
- Fan Pressure Indication
- Duct, Room or Building Pressures
- Clean Room Positive Pressure Indication
Models & Ordering
- Air and non-combustible, compatible gases. (Natural Gas option available.)
- Wetted Materials:
- Consult factory.
- Die cast aluminum case and bezel, with acrylic cover, Exterior finish is coated gray to withstand 168 hour salt spray corrosion test.
- Pressure Limits:
- -20 in Hg. to 15 psig.† (-0.677 bar to 1.034 bar); MP option; 35 psig (2.41 bar), HP option; 80 psig (5.52 bar).
- Relief plug opens at approximately 25 psig (1.72 bar), standard gages only. See Overpressure Protection note on Catalog page.
- Temperature Limits:
- 20 to 140°F.* (-6.67 to 60°C).
- Mounting Orientation:
- Diaphragm in vertical position. Consult factory for other position orientations.
- Process Connections:
- 1/8" female NPT duplicate high and low pressure taps - one pair side and one pair back.
- 1 lb 2 oz (510 g); MP & HP 2 lb 2 oz (963 g).
- Standard Accessories:
- Two 1/8" NPT plugs for duplicate pressure taps, two 1/8" pipe thread to rubber tubing adapters and three flush mounting adapterswith screws. (Mounting and snap ring retainer substituted for three adapters in MP & HP gage accessories.)
- *Low temperature models available as special option.
- †For applications with high cycle rate within gage total pressure rating, next higher rating is recommended. See Options Page.
- Agency Approval:
- RoHS. (Note: -SP models not RoHS approved.)
- ±2% of FS (±3% on -0, -100PA, -125PA, -10MM and ±4% on -00, -60PA, -6MM ranges), throughout range at 70°F (21.1°C).
- May be used with hydrogen. Order a Buna-N diaphragm. Pressures must be less than 35 psi.
- 4" (101.6 mm) diameter dial face.
- Bezel provides flange for flush mounting in panel.
- Clear plastic face is highly resistant to breakage. Provides undistorted viewing of pointer and scale.
- Precision litho-printed scale is accurate and easy to read.
- Red tipped pointer of heat treated aluminum tubing is easy to see. It is rigidly mounted on the helix shaft.
- Pointer stops of molded rubber prevent pointer over-travel without damage.
- "Wishbone" assembly provides mounting for helix, helix bearings and pointer shaft.
- Jeweled bearings are shock-resistant mounted; provide virtually friction-free motion for helix. Motion damped with high viscosity silicone fluid.
- Zero adjustment screw is conveniently located in the plastic cover, and is accessible without removing the cover. O-ring seal provides pressure tightness.
- Helix is precision made from an alloy of high magnetic permeability. Mounted in jeweled bearings, it turns freely, following the magnetic field to move the pointer across the scale.
- Calibrated range spring is flat spring steel. Small amplitude of motion assures consistency and long life. It reacts to pressure on diaphragm. Live length adjustable for calibration.
- Silicone rubber diaphragm with integrally molded O-ring is supported by front and rear plates. It is locked and sealed in position with a sealing plate and retaining ring. Diaphragm motion is restricted to prevent damage due to overpressures.
- Die cast aluminum case is precision made and iridite-dipped to withstand 168 hour salt spray corrosion test. Exterior finished in baked dark gray hammerloid. One case size is used for all standard pressure options, and for both surface and flush mounting.
- OVERPRESSURE PROTECTION
Blowout plug is comprised of a rubber plug on the rear which functions as a relief valve by unseating and venting the gage interior when over pressure reaches approximately 25 psig (1.7 bar). To provide a free path for pressure relief, there are four spacer pads which maintain 0.023" clearance when gage is surface mounted. Do not obstruct the gap created by these pads. The blowout plug is not used on models above 180" of water pressure, medium or high pressure models, or on gages which require an elastomer other than silicone for the diaphragm. The blowout plug should not be used as a system overpressure control. High supply pressures may still cause the gage to fail due to over pressurization, resulting in property damage or serious injury. Good engineering practices should be utilized to prevent your system from exceeding the ratings or any component.
- O-ring seal for cover assures pressure integrity of case.
- Samarium Cobalt magnet mounted at one end of range spring rotates helix without mechanical linkages.
- ASF Adjustable Signal Flag
- HP High Pressure Option
- LT Low Temperatures to -20°F
- MP Med. Pressure Option
- SP Setpoint Indicator
- Scale Overlays Red, Green, Yellow, Mirrored or Combination, Specify Locations
A single case size is used for most models of Magnehelic® gages. They can be flush or surface mounted with standard hardware supplied. Although calibrated for vertical position, many ranges above 1" may be used at any angle by simply re-zeroing. However, for maximum accuracy, they must be calibrated in the same position in which they are used. These characteristics make Magnehelic® gages ideal for both stationary and portable applications. A 4-9/16" hole is required for flush panel mounting. Complete mounting and connection fittings, plus instructions, are furnished with each instrument.
|Model Number||Description||Usually Ships||Price||Order|
|A-321||Brass safety relief valve, protects Magnehelic® gage or Photohelic® switch/gage against over pressure due to regulator failure, etc, opens at 10 psi. Mounts in tee fitting. 1/4" NPT(M) (use two for DP application). .5" x .5" x 1.5", .10 .lb||Same Day||$36.50||Order|
|A-605||Air filter kit - adapts any standard Magnehelic® gage for use as an air filter gage. Includes aluminum surface mounting bracket with screws, (2) 5 ft (1.5 m) lengths of 1/4" aluminum tubing, (2) static pressure tips & (2) molded plastic vent valves.||Same Day||$36.25||Order|
|A-610||Pipe mounting kit for 1-1/4" to 2" pipe. 5.6" x 4.6" x 1.4", 1.0 .lb||Same Day||$26.50||Order|
|A-300||Flat aluminum bracket for flush mounting Magnehelic® gage. 6.8" x 6.0" x .1", .35 lb.||Same Day||$26.75||Order|
|A-310A||3-way vent valve, plastic, 1/8" NPT to 1/4" metal tubing, 80 psi rating, replaces former Model A-310 (brass). 2.3" x .8" x .1", .10 lb.||Same Day||$17.50||Order|
|A-432||Plastic carrying case for Magnehelic® gage of standard range, except high pressure connection, includes 9 ft (2.7m) of 3/16" ID rubber tubing, stand-hang bracket & terminal tube with holder. 9.1" x 7.4" x 3.6", 1.30 .lb||Same Day||$48.00||Order|
|A-464||Flush mount kit for Magnehelic® gages.||Same Day||$20.00||Order|
|SWUK1||Strap wrench. 14.6" x 5.8" x 1.3", .55 .lb||Consult Factory||$32.00||Order|
|A-448||3-piece magnet kit for mounting Magnehelic® gage directly to a magnetic surface, 3.3" x 1.7" x .5", .20 .lb||Same Day||$10.75||Order|
|A-320-A||Enclosure for Series 2000 Magnehelic® Gages, DM-2000 Differential Pressure Transmitter, 4-9/16" (115.89 mm).||Same Day||$165.00||Order|
|A-605B||Air filter kit with (2) plastic open/close valves, (2) 4' steel static tips, tubing & mounting flange.||Same Day||$27.50||Order|
|A-605C||Air filter kit with (2) plastic open/close valves, (2) plastic static tips, tubing & mounting flange.||Same Day||$22.25||Order|
|A-135||Rubber gasket for panel mounting.||Same Day||$1.50||Order|
|A-369||Stand-hang bracket, aluminum, for Magnehelic® gage.||Same Day||$12.00||Order|
|A-368||Surface mounting plate, aluminum, for Magnehelic® gage.||Same Day||$6.60||Order|
|A-371||Surface mounting bracket, use with Photohelic® switch/gage on horizontal or vertical surfaces, also for Capsu-Photohelic® switch/gage on vertical only. Also Magnehelic® -MP, -HP models.||Same Day||$37.75||Order|
|A-286||4-1/2" Gage panel mounting flange||Same Day||$9.99||Order|
|A-401||Plastic carrying case (7-9/16" x 5-7/8" x 2-13/16").||Same Day||$26.25||Order|
|A-299||Mounting bracket flush mount Magnehelic® gage in bracket. Bracket is then surface mounted . Steel with gray hammertone epoxy finish. 6.3" x 7.7" x 4.0", 1.30 lb.||Same Day||$31.00||Order|
|A-607||Mounting panel for Magnehelic®.||1-2 Weeks||$2.75||Order|
|2000-00N||ASF||Series 2000-00N-ASF Magnehelic® Differential Pressure Gage, range .05-0-.20" w.c., with adjustable signal flag.|
0-1 ft w.c.
0-1.5 ft w.c.
0-2 ft w.c.
0-2.5 ft w.c.
0-3 ft w.c.
0-4 ft w.c.
0-5 ft w.c.
0-6 ft w.c.
0-8 ft w.c.
0-10 ft w.c.
0-12 ft w.c.
0-12.5 ft w.c.
0-15 ft w.c.
0-20 ft w.c.
0-25 ft w.c.
0-30 ft w.c.
0-35 ft w.c.
0-40 ft w.c.
0-50 ft w.c.
0-60 ft w.c.
0-0.25" w.c. & 0-62 Pa
0-0.5" w.c. & 0-125 Pa
0-1" w.c. & 0-250 Pa
0-2" w.c. & 0-500 Pa
0-3" w.c. & 0-750 Pa
0-4" w.c. & 0-1 kPa
0-5" w.c. & 0-1.25 kPa
0-6" w.c. & 0-1.5 kPa
0-8" w.c. & 0-2 kPa
0-10" w.c. & 0-2.5 kPa
0-15" w.c. & 0-3.7 kPa
0-20" w.c. & 0-5 kPa
0-25" w.c. & 0-5.2 kPa
0-30" w.c. & 0-7.5 kPa
0-40" w.c. & 0-10 kPa
00-50" w.c. & 0-12.4 kPa
0-60" w.c. & 0-15 kPa
0-100" w.c. & 0-25 kPa
0-200" w.c. & 0-50 kPa
5-0-5" w.c. & 1.25-0-1.25 kPa
0-0.25" w.c. & 0-2000 fpm
0-0.5" w.c. & 0-2800 fpm
0-1" w.c. & 0-4000 fpm
0-2" w.c. & 0-5600 fpm
0-5" w.c. & 0-8800 fpm
0-10" w.c. & 0-12500 fpm
0-15" w.c. & 0-15500 fpm
0-20" w.c. & 0-17500 fpm
0-25" w.c. & 0-20000 fpm
0-60 Pa & 0-9.8 m/s
0-125 Pa & 0-14.4 m/s
0-250 Pa & 0-20 m/s
0-500 Pa & 0-28 m/s
0-1.25 kPa & 0-45 m/s
0-2 kPa & 0-57 m/s
0-3.5 kPa & 0-76 m/s
0-5 kPa & 0-90 m/s
0-6 kPa & 0-98 m/s
0-0.5 mm Hg
0-1 mm Hg
0-2 mm Hg
0-4 mm Hg
0-5 mm Hg
0-6 mm Hg
0-7 mm Hg
0-8 mm Hg
0-9 mm Hg
0-10 mm Hg
0-11 mm Hg
0-12 mm Hg
0-15 mm Hg
0-20 mm Hg
0-25 mm Hg
0-30 mm Hg
0-35 mm Hg
0-40 mm Hg
0-50 mm Hg
0-60 mm Hg
0-80 mm Hg
0-100 mm Hg
0-150 mm Hg
0-200 mm Hg
0-250 mm Hg
0-300 mm Hg
0-350 mm Hg
0-400 mm Hg
30-0-30 mm Hg
0-6 mm w.c.
0-8 mm w.c.
0-10 mm w.c.
0-12 mm w.c.
0-15 mm w.c.
0-20 mm w.c.
0-25 mm w.c.
0-30 mm w.c.
0-35 mm w.c.
0-40 mm w.c.
0-50 mm w.c.
0-60 mm w.c.
0-75 mm w.c.
0-80 mm w.c.
0-100 mm w.c.
0-125 mm w.c.
0-150 mm w.c.
0-200 mm w.c.
0-250 mm w.c.
0-300 mm w.c.
0-350 mm w.c.
0-375 mm w.c.
0-400 mm w.c.
0-500 mm w.c.
0-600 mm w.c.
0-700 mm w.c.
0-750 mm w.c.
0-800 mm w.c.
0-100 x 10 mm w.c.
0-120 x 10 mm w.c.
0-150 x 10 mm w.c.
0-160 x 10 mm w.c.
0-180 x 10 mm w.c.
0-200 x 10 mm w.c.
0-300 x 10 mm w.c.
0-400 x 10 mm w.c.
0-500 x 10 mm w.c.
3-0-3 mm w.c.
5-0-5 mm w.c.
6-0-6 mm w.c.
7-0-7 mm w.c.
10-0-10 mm w.c.
15-0-15 mm w.c.
20-0-20 mm w.c.
25-0-25 mm w.c.
30-0-30 mm w.c.
40-0-40 mm w.c.
50-0-50 mm w.c.
75-0-75 mm w.c.
80-0-80 mm w.c.
100-0-100 mm w.c.
125-0-125 mm w.c.
150-0-150 mm w.c.
160-0-160 mm w.c.
200-0-200 mm w.c.
225-0-225 mm w.c.
250-0-250 mm w.c.
300-0-300 mm w.c.
350-0-350 mm w.c.
375-0-375 mm w.c.
400-0-400 mm w.c.
500-0-500 mm w.c.
0-1.5 cm w.c.
0-2 cm w.c.
0-2.5 cm w.c.
0-3 cm w.c.
0-4 cm w.c.
0-5 cm w.c.
0-6 cm w.c.
0-8 cm w.c.
0-10 cm w.c.
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0-60 cm w.c.
0-80 cm w.c.
0-100 cm w.c.
0-125 cm w.c.
0-150 cm w.c.
0-200 cm w.c.
0-250 cm w.c.
0-300 cm w.c.
0-350 cm w.c.
0-400 cm w.c.
0-500 cm w.c.
0-600 cm w.c.
0-700 cm w.c.
0-100 x 10 cm w.c.
1-0-1 cm w.c.
1.5-0-1.5 cm w.c.
2-0-2 cm w.c.
2.5-0-2.5 cm w.c.
5-0-5 cm w.c.
10-0-10 cm w.c.
15-0-15 cm w.c.
20-0-20 cm w.c.
25-0-25 cm w.c.
30-0-30 cm w.c.
40-0-40 cm w.c.
50-0-50 cm w.c.
0-100 x 10 Pa
0-125 x 10 Pa
0-150 x 10 Pa
0-200 x 10 Pa
0-250 x 10 Pa
0-300 x 10 Pa
0-450 x 10 Pa
0-500 x 10 Pa
0-600 x 10 Pa
0-800 x 10 Pa
100-0-100 x 10 Pa
150-0-150 x 10 Pa
250-0-250 x 10 Pa
300-0-300 x 10 Pa
0-100 x 10 Millibar
0-0.5 ounces per square inch
0-1 ounces per square inch
0-2 ounces per square inch
0-3 ounces per square inch
0-4 ounces per square inch
0-6 ounces per square inch
0-8 ounces per square inch
0-10 ounces per square inch
0-15 ounces per square inch
0-16 ounces per square inch
0-20 ounces per square inch
0-30 ounces per square inch
0-32 ounces per square inch
0-40 ounces per square inch
0-50 ounces per square inch
0-80 ounces per square inch
0-100 ounces per square inch
1-0-1 ounces per square inch
0-10" w.c. & 0-20 SCFM air (w/1" NPT Tube)
0-10" w.c. & 0-50 SCFM air (w/1.5" NPT Tube)
0-10" w.c. & 0-85 SCFM air (w/2" NPT Tube)
0-10" w.c. & 0-200 SCFM air (w/3" NPT Tube)
0-10" w.c. & 0-350 SCFM air (w/4" NPT Tube)
0-20" w.c. & 0-30 SCFM air (w/1" NPT Tube)
0-20" w.c. & 0-70 SCFM air (w/1.5" NPT Tube)
0-20" w.c. & 0-120 SCFM air (w/2" NPT Tube)
0-20" w.c. & 0-290 SCFM air (w/3" NPT Tube)
0-20" w.c. & 0-500 SCFM air (w/4" NPT Tube)
0-40" w.c. & 0-40 SCFM air (w/1" NPT Tube)
0-40" w.c. & 0-100 SCFM air (w/1.5" NPT Tube)
0-40" w.c. & 0-160 SCFM air (w/2" NPT Tube)
0-40" w.c. & 0-395 SCFM air (w/3" NPT Tube)
0-40" w.c. & 0-675 SCFM air (w/4" NPT Tube)
|Adjustable Signal Flag
Certificate of Origin
Green Scale Overlay
Mirror Scale Overlay
NIST Certificate of Calibration
Red Scale Overlay
304 Stainless Steel Bezel
Stainless Steel Tag
Tilt Angle from Vertical in Degrees
Yellow Scale Overlay
- Instruction Manual (HP or MP Option)
- Instruction Manual (A-610/Pipe Mtg Kit)
- Instruction Manual (Air Filter Gages)
- Instruction Manual - English
- Instruction Manual - Spanish
- How will installation of a Magnehelic® gage 150' away from the pressure source affect accuracy?
- Accuracy will not be affected, but response time will be increased in proportion to the length of the tubing.
- Can the standard Magnehelic® or Capsuhelic® gage be installed outdoors?
- Yes. Front covers are sealed with "O" rings. Capsuhelic vent holes are plugged with foam, and the new high impact acrylic lens material is very resistant to ultra-violet fogging. Additional care is recommended to lead pressure connections downward from the gage and provide as much protection from the elements as possible
- Can a standard Magnehelic® gage be used for natural gas or propane service?
- No. As the silicone diaphragm will be attacked by these gases. A Buna-N diaphragm should be specified.
- What happens when a Magnehelic® gage equipped with the low temperature option is operated below -20 degrees Fahrenheit (-29 degrees Celsius)?
- Below that temperature the accuracy of the gage deteriorates beyond our published specification due to stiffening of the diaphragm.
- What restrictions, if any, are imposed for the Magnehelic® and Photohelic® gages in vacuum service?
- In applications involving higher vacuums than 20" Hg, leakage due to gage housing porosity becomes the limiting factor.
- Is National Institute of Standards and Technology traceability available for the Magnehelic® Gage?
- No. But Magnehelic® gages can be given a special 6 point calibration check with an NIST traceable master gage and a certificate can be supplied.
- How do I hook up my Magnehelic® Gage?
- In Bulletin A-27 under operation, it explains how to connect the Magnehelic to the following applications: positive pressure, negative pressure, and differential pressure.
- How do I hook up my Magnehelic® gage for an air velocity application with a pitot tube?
- In our Application Guides on flow products, we explain very well how to take air velocity readings. The total pressure connection on the pitot tube is connected to one of the high pressure ports on the gage. The other high pressure port is plugged. The static pressure connection on the pitot tube is connected to one of the low pressure ports on the gage. The other low pressure port is plugged.
- Are air velocity scales available?
- Yes, the information we require to supply the proper range is the velocity (fpm or m/s) or velocity pressure (inches of water or kpa) and density of air (lb/ft3 or g/cm3).
- Why must Dwyer pressure switches be mounted with the diaphragm in the vertical plane?
- In other than a vertical plane, the diaphragm can sag and cause a shift in set-point or a change in the adjustable set-point range. The switch may even fail to reset at the minimum set-points. This is the same phenomena that causes inaccuracy in Magnehelic® and Capsuhelic® gages when mounted in other than a vertical position.
- Can the ASF option be used as a tattle tell? Or do you have something that could be used as a tattle tell on the 2000 series DP gages?
- The ASF option cannot be used as a tattle tell. It is just there for visual indication of a set point. We have nothing with our 2000 series that can act as a tattle tell, however our series DM-1000 DigiMag will have a peak valve function built in.
- Your Magnehelic gauge doesn't come with a calibration certificate, do you have any documentation for these gauges to meet these needs?
- We have 3 options: (1) We can supply a Certificate of Conformance at no charge if you request that certificate at the time of order. The Certificate of conformance would state that each Magnehelic gauge is calibrated to meet the specifications stated on the spec sheet. (2) We offer a factory calibration “-FC” as an option that is a certificate of the standard calibration points at the time of manufacture, for a small fee. (3) We can also provide a NIST-traceable calibration for an extra charge per gage if that is required. To get the NIST-traceable calibration, you would simply add a “-NIST” to the end of your part number. NIST-traceable calibrations will come with the 6 point calibration certificate. We recommend “periodic calibration” for our Magnehelic, though we leave the specific time-frame up to the end user, since different organizations have different requirements (i.e. government groups often require more frequent calibrations.) If you choose to have the NIST traceable calibration done, the NIST group (the National Institute of Standards and Technology) dictates yearly calibration and it will be printed on the certificate.
- What might be the cause for Magnehelic® gages filling approximately 1/3 full of water, with lots of liquid droplets on the glass. Both are outside mounted on the side of an air stripping tower. One is a differential pressure gage that measures the pressure drop across a pitot tube. The other just measures the back pressure in the stripper. What can be done to fix the malfunction?
- It looks like you’re getting some condensation in the Magnehelic®, which is causing it to collect on the bottom of the face. Since the Magnehelic® is not encapsulated, it is not recommended to be used in applications where moisture can form. One option to fix the problem is installing a liquid filter (like an F222) to filter out that moisture. Another option is to install a Capsuhelic (Series 4000), which is made to handle both air and liquid.
- Can the Vaneometer model 480 be equipped with a scale to read in inches of water? We want to use the vaneometer to assure we have a pressure differential of -0.01 wc when measured at the door gap to a patient isolation room.
- The series 480 does not come with a scale reading in inches w.c., the scales would be in velocity units to read air velocity. However, we do have differential pressure gages or manometers than can be used to measure the differential pressure in an inches w.c. scale. I would recommend taking a look at our Series 2000 Magnehelic® Differential Pressure Gage, as we do have many customers use these for clean room applications. We have the model number 2000-00N which has a range of 0-0.2. and the major grads will be 0.01” w.c.
- I have a Dwyer Magnehelic, can I pressure test a furnace gas valve with natural gas with this instrument?
- The standard Magnehelic is not recommended for use with natural gas. For natural gas applications, we would recommend a Magnehelic with a Buna-N diaphragm and an oil impregnated case for better chemical compatibility and a reduced leak rate respectively.
- Is the Magnehelic 2000 suitable for use in a Class 1 Div 1 environment?
- The 2000 Series Magnehelic Differential Pressure Gauge is purely a mechanical gauge with no electronics, so it can be considered a simple apparatus. However, it does not have any explosion proof ratings. Furthermore, there will be a small leak rate through the cast aluminum housing. The standard unit is designed for air and non-combustible compatible gases. The Magnehelic can be used with certain compatible combustible gases, but we would recommend a Buna-N diaphragm and an oil impregnated case for chemical compatibility and a reduced leak rate respectively. Even with these options though, the unit still will not officially have any explosion proof ratings.
- For the Series 2000 Magnehelic Differential Pressure Gauges, what panel mounts are compatible with the A-135 rubber gasket?
- Any of our panel or flush mounting brackets will work with the A-135 rubber gasket. The rubber gasket just gives you a tight seal between the Magnehelic’s bezel and the bracket.
- I am looking to measure velocity in a 4" pipe that is used as air conveyance. We use an eductor and a single stage blower to produce air flow. I am looking to measure pressure and velocity. I purchased a Dwyer Pitot tube, 167-7 108024-00 for the job, and I want to match with the right gauge. I need to be in the range of 2600 cuft/min at maybe 0.5psi. Can you direct me to the right gauge with that information?
- To monitor flow through your 4” pipe, you will have to size the appropriate differential pressure gage. A very common gage that is used will be our Series 2000 Magnehelic gage. This gage can be ordered with a square root output that will direct read in flow units. Upon ordering this part, you will have to specify the maximum differential pressure at your desired flow rate. The following text will bring you to the equations necessary to compute this differential (velocity) pressure. This can also be found in the APPLICATION GUIDES section of our website.
- What is the advantage of using a manometer rather than a Magnehelic® gage?
- Dwyer Instruments manufactures many different types and styles of manometers with various accuracies and prices for different applications as well as the Magnehelic® gage. For example, some of the many manometers we manufacture are Hook Gage Manometers with ±0.001 inches water column accuracy; Microtector® Portable Electronic Point Gage to ±0.00025 inches water column accuracy; Handheld Digital Manometers with ±0.5 inches water column accuracy; very inexpensive Mark II Molded Plastic Air Filter Gages at ±3% inches water column accuracy. The key point is that we offer many manometers and the selection depends on your specification, application, convenience needs and pocketbook. Some of the key factors to consider that affect manometer performance and usage are: Characteristics of Indicating Fluid, Readability and Leveling. You should read "Measurement of Pressure with the Manometer" in our catalog to fully understand the importance of these factors and their effect on your reading with the manometer instrument. For many applications people prefer to use our Magnehelic® (dial style) gage with ±2% inches of water column accuracy because of convenience, accuracy, etc., plus when compared to a manometer, it eliminates indicating fluid, need for leveling, and some prefer the readability. If you consider manometers and Magnehelic® gages to measure low air or gas pressures positive, negative, or differential, you have a wide selection to choose from and your application needs can be met with our very broad product line at a great value.
- What is the best method of measuring actual air flow in process ducts to verify process air flow sensors (differential pressure sensors, air flow stations, etc.)
- There are two ways to measure air flow in process ducts. The most common means is the use of a Series 2000 Magnehelic® Differential Pressure Gage. This gage can be ordered with a square root output that will read in flow units. You will have to specify the maximum differential pressure at your desired flow rate. Along with the gage, a pitot tube (connected by means of rubber or vinyl tubing) is also used. The pitot tube must be pointed directly into the air stream. Care must be taken to ensure that the pitot tube should be inserted at least 8-1/2 duct diameters downstream from elbows, bends or other obstructions which cause turbulence. The alternative method uses a 100 AV Durablock® Air Velocity Gage kit. The kit includes a manometer, a stainless steel pitot tube, rubber tubing with connectors, and red gage fluid. The pitot tube, pointed directly into the air stream, senses total and static pressure. The manometer then senses velocity pressure (difference between total and static pressure).
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