Description
The Schaffer Diaphragm Pressure Gauge by Aavad Instrument Pvt. Ltd. is a robust, direct-acting diaphragm pressure gauge specially designed for measuring low to medium pressures of viscous, corrosive, crystallizing, or media that tend to block conventional Bourdon tube or capsule gauges. Unlike diaphragm-sealed (chemical seal) gauges that use a fill fluid, the Schaffer design uses a direct mechanical linkage from the diaphragm to the pointer through a precisely engineered lever-and-pinion movement — eliminating fill fluid and reducing hysteresis.
Manufacturing Diaphragm pressure gauges are used to measure gases and liquids. They cover measuring spans from 10 mbar to 40 bar. The measuring element consists of one circular diaphragm clamped between a pair of flanges.
Key Features
- Sensing Element: Large corrugated diaphragm (SS 316L / Hastelloy / PTFE / Rubber) for direct low-pressure measurement
- Pressure Range: 10 mbar to 40 bar (1 mbar vacuum ranges also available)
- Dial Size: 100 mm, 160 mm for clear field reading
- Movement: Direct mechanical Schaffer lever-and-segment design — no fill fluid required
- High overload protection: Diaphragm bottoms out safely without permanent deformation
- Accuracy: ±1.6% FSD (EN 837-3)
- Process Connection: ¼” BSP, ½” BSP, or flanged (PN 10/16) bottom or back entry
- Wetted Parts: SS 316L, Hastelloy C, PTFE-coated or elastomer diaphragm per media
- Dry (non-filled) design avoids fill fluid contamination risk
- Chemical resistance: Compatible with acids, bases, and mild solvents per diaphragm selection
- Optional flush (zero dead volume) diaphragm for slurry and paste media
- Available with electrical contact outputs for alarm or automation
- Can be configured for vacuum, compound (negative and positive), and gauge pressure
Applications
- Wastewater and sewage treatment — sludge and slurry pressure measurement
- Chemical dosing systems — acid, alkali, and caustic pressure monitoring
- Low-pressure pneumatic conveying systems
- Paint, lacquer, and resin process lines
- Food processing — dough, paste, and semi-solid media
- Pharmaceutical manufacturing — cream, gel, and suspension pressure control
- HVAC condensate and chilled water low-pressure monitoring
- Agricultural chemical and pesticide blending
- Polymer and rubber compounding pressure monitoring
- Biogas and landfill gas low-pressure measurement
Datasheet
FAQs
1. What is a Capsule Diaphragm Gauge?
A Capsule Diaphragm Gauge is a low-pressure mechanical pressure gauge that uses a corrugated metallic capsule to accurately measure low positive pressure, vacuum, and differential pressure in dry, non-corrosive gases and air. It is commonly used where precise measurement of very low pressures is required.
2. How does a Capsule Diaphragm Gauge work?
The gauge contains two thin corrugated metallic diaphragms joined together to form a sealed capsule. As the applied pressure changes, the capsule expands or contracts. This mechanical movement is transferred through a linkage mechanism to the pointer, which indicates the corresponding pressure on the calibrated dial.
3. What pressure range does this model measure?
This model measures pressures up to 1000 mmWC (millimetres of water column). Aavad Instrument Pvt. Ltd. also offers custom low-pressure ranges to suit specific applications involving low-pressure gas, air, vacuum, and differential pressure measurement.
4. Can this Gauge measure Liquids?
No. A Capsule Diaphragm Gauge is designed exclusively for measuring dry, non-corrosive gases and air. It is not suitable for liquids, slurry, viscous media, steam, or corrosive chemicals, as these media can damage the capsule element and affect measurement accuracy.
