HE27 Vacuum/Absolute Pressure Sensor

Gauge pressure measures relative to atmospheric pressure (0 = ambient), while absolute pressure measures relative to a perfect vacuum (0 = complete vacuum). For vacuum applications like semiconductor processing or freeze-drying, absolute pressure is typically preferred because it provides a stable reference unaffected by weather and altitude changes. The HE27 gauge variants (G) cover -1 bar to 0 range for vacuum-relative measurement, while absolute variants (A) measure from 0 bar absolute up to 35 bar, giving true zero-reference readings essential for precise vacuum control.

Yes. The gauge-type HE27 with range code ZF1B covers -1 bar to +1 bar, allowing measurement of both vacuum (negative gauge) and positive pressure in a single sensor. This compound range is ideal for systems that cycle between vacuum and positive pressure stages, such as autoclave sterilizers and vacuum-pressure impregnation processes. For wider positive pressure ranges combined with vacuum, select the appropriate absolute pressure range variant.

For applications requiring full vacuum to atmospheric measurement, choose the 0F1B range (-1 bar to 0 gauge) or the 001B range (0–1 bar absolute). The 1R1B range (0–1.1 bar absolute) provides slight overpressure tolerance. For vacuum systems that also see positive pressure, the ZF1B compound range (-1 to +1 bar gauge) is ideal. For higher positive pressure requirements with vacuum capability, absolute ranges from 002B (2 bar) to 035B (35 bar) are available. Always select a range where your normal operating pressure falls within 20–80% of full scale for optimal accuracy.

Piezoresistive vacuum sensors suffer from three key issues: (1) measurement instability at sub-atmospheric pressures due to silicon strain gauge sensitivity to temperature gradients; (2) long-term zero drift that worsens at low pressures; (3) limited overload protection. The HE27’s silicon thin-film capacitive technology inherently avoids these problems — capacitive sensing is more stable at low pressures, shows minimal zero drift (±0.2% FS/year), and the robust stainless steel diaphragm provides 1.5–2× overload protection with 300% transient shock capability.

Standard HE27 configurations with common range and output combinations are typically available within 2–3 weeks. Custom configurations — including non-standard pressure ranges, special thread connections (F0 option), or modified output signals — are available for volume orders. Contact our engineering team with your specific requirements, quantities, and application details for a customized quotation.