India's trusted source for Magnehelic gauges — also known as Magnahelic gauges or differential pressure indicators. We supply all ranges, all brands, with expert application support for HVAC, cleanrooms, pharma & industrial applications.
A Magnehelic gauge (also commonly spelled Magnahelic gauge) is a precision differential pressure indicator used to measure the difference in pressure between two points. It is specifically designed for measuring low differential pressures of air and non-corrosive gases.
Unlike ordinary pressure gauges, the Magnehelic uses a patented frictionless movement — a diaphragm-and-magnet mechanism — that eliminates all pivots, bearings, and levers. This makes it highly accurate, maintenance-free, and extremely long-lasting even in continuous industrial use.
The term Magnehelic is often used generically for any differential pressure gauge of this type, though it was originally trademarked by Dwyer Instruments, USA. Equivalent instruments are also manufactured by Gallaxy, Sensocon, and Teren.
| Measurement Type | Differential Pressure (Low Range) |
| Media | Air & Non-corrosive Gases |
| Accuracy | ±2% Full Scale |
| Ranges Available | 0–0.25" WC to 0–300" WC / Pa / mbar / mmWC |
| Display | Analogue Dial — No Power Required |
| Connection | 1/8" NPT (High & Low pressure ports) |
| Dial Size | 4" (100mm) standard |
| Mounting | Panel / Surface / Pipe mounting |
| Body Material | Die-cast Aluminium / Plastic (brand dependent) |
| Operating Temp | –18°C to +65°C |
| Overpressure | Typically 25–35 PSI |
The Magnehelic gauge uses a unique frictionless diaphragm-magnet system — no pivots, no bearings, no fluid. Here's how it works step by step.
High and low pressure connections are made to the two ports on the back of the gauge. The pressure difference causes the internal diaphragm to flex.
A precision-formed diaphragm responds proportionally to the differential pressure. Its movement is extremely sensitive — capable of detecting very small pressure differences.
The diaphragm movement is magnetically coupled to a pointer mechanism — with no mechanical linkage. This eliminates friction, wear, and hysteresis errors entirely.
The pointer rotates proportionally across the calibrated scale, indicating the exact differential pressure reading with ±2% full scale accuracy. No power needed.
We are authorised suppliers for four leading Magnehelic gauge brands — from the original American inventor to trusted Indian manufacturers. All brands available in stock.
Dwyer Instruments invented the Magnehelic gauge and holds the original trademark. The Dwyer Series 2000 Magnehelic gauge is the world's most widely used differential pressure indicator, trusted in pharmaceutical, HVAC, and critical industrial applications globally. Known for highest accuracy, reliability, and the widest range selection.
Gallaxy is one of India's most reputable manufacturers of differential pressure gauges. Their Magnehelic-equivalent gauges are widely used across Indian pharmaceutical, HVAC, and process industries. Gallaxy offers excellent quality at competitive Indian pricing with quick delivery across India.
Sensocon manufactures high-quality differential pressure gauges widely used in HVAC systems, clean rooms, and industrial process applications across India. Their products are known for robust construction, consistent accuracy, and long service life in demanding environments.
Teren offers reliable and affordable Magnehelic-type differential pressure gauges suitable for standard HVAC, filter monitoring, and general industrial applications. An excellent choice where cost-effectiveness is important without compromising on fundamental accuracy and reliability.
Available in a wide selection of pressure ranges and units. All ranges available in Dwyer, Gallaxy, Sensocon, and Teren brands. Contact us to confirm current stock.
For cleanrooms, laminar flow cabinets, and critical pharmaceutical environments requiring very sensitive pressure differential measurement.
Most commonly used range for HVAC filter monitoring, duct pressure, and general cleanroom pressure differential applications.
Suitable for fan and blower performance measurement, industrial filter ΔP, and duct system balancing in large HVAC systems.
For industrial applications with higher differential pressures — large industrial blowers, dust collectors, and process equipment.
Available in Pascal (Pa) and millibar (mbar) units for projects requiring metric pressure units — commonly specified in European-designed systems.
Millimetres of water column (mmWC) units are widely preferred in Indian industrial projects, boiler rooms, and process industries.
Measures both positive and negative differential pressure — useful for applications where pressure can swing in either direction, such as room pressure in containment facilities.
Special ranges, dual-scale dials, coloured scale zones, or custom face printing available for OEM and project-specific requirements. Contact us for details.
Magnehelic differential pressure gauges are used across a wide range of industries and applications wherever accurate low differential pressure measurement is needed.
Monitoring positive / negative pressure differentials between cleanroom zones, isolators, and pass-through areas. Essential for GMP compliance and contamination control.
Measuring pressure drop across air handling unit (AHU) filters to determine when filter replacement is required. Prevents energy waste and ensures clean air supply.
Measuring static pressure in HVAC duct systems for system balancing, commissioning, and performance verification of air distribution networks.
Monitoring fan inlet and outlet pressure to verify fan performance, detect blade wear, and ensure the fan is operating at the designed duty point.
Verifying HEPA filter integrity and airflow in laminar flow workstations, biosafety cabinets, and pharmaceutical dispensing booths.
Monitoring pressure drop across industrial dust collectors, bag filters, cartridge filters, and process gas filters for timely maintenance scheduling.
Measuring exhaust filter condition and booth pressure in automotive and industrial paint spray booths for safety and finish quality assurance.
Monitoring stairwell and corridor pressurisation systems in high-rise buildings for fire safety compliance and smoke control verification.
Fume hood face velocity monitoring, biosafety cabinet verification, and general low differential pressure measurement in R&D and testing laboratories.
Complete your installation with the right accessories. We supply all accessories along with the gauge for a complete, ready-to-install solution.
Stainless steel static pressure probes for insertion into ducts. Essential for accurate static pressure measurement in air handling systems.
Standard and averaging pitot tubes for measuring total and velocity pressure in HVAC ducts and stacks. Available in various insertion lengths.
High and low limit alarm switches that mount directly on the gauge. Provide electrical signal when pressure exceeds or falls below set points.
IP65 rated enclosures for outdoor or wet area installations. Protects the gauge from moisture, dust, and harsh environmental conditions.
Flush panel mounting rings and surface mounting brackets for neat installation on control panels and instrument boards.
Flexible rubber tubing kits with fittings for connecting gauge ports to pressure tapping points. Available in various lengths.
Pulsation snubbers and isolation valves to protect the gauge from pressure spikes and allow safe removal for maintenance.
Multi-point averaging manifolds for sensing average pressure across duct cross-sections — improves accuracy in large duct applications.
We are more than just a supplier — we are your instrumentation partner. Here's what sets us apart.
Authorised dealer for Dwyer, Gallaxy, Sensocon, and Teren. All products are genuine, with manufacturer warranty and documentation.
We don't just sell — we help you select the right range, brand, and accessories for your specific application and process conditions.
Popular ranges are maintained in stock for immediate dispatch. Most orders dispatched within 1–2 working days.
Datasheets, calibration certificates, test reports, and MSDS provided on request — essential for pharma and regulated industries.
We deliver to all major cities and industrial areas across Tamil Nadu and India — Chennai, Coimbatore, Bengaluru, Mumbai, Hyderabad and more.
Our team is available to assist with installation queries, troubleshooting, and replacement after your purchase.
Tell us your requirement — range, brand preference, quantity, and application — and we'll respond within 24 hours with the best price.
For urgent requirements, call or WhatsApp us directly. We'll help you select the right gauge and provide a competitive quote immediately.
💬 WhatsApp Us for Quick QuoteCommon questions about Magnehelic gauges — answered by our instrumentation experts.