What is the Cerabar PMP23?

The Cerabar PMP23 is a compact, hygienic pressure transmitter designed to measure process pressure in liquids and gases. It is used widely in food-and-beverage, pharmaceutical, and other hygienic industries because of its flush-mounted 316L diaphragm, robust design and certifications (EHEDG, 3-A, FDA, EG1935/2004).

Typical specifications include:

• Pressure range: ~400 mbar to 40 bar (6 to 600 psi)
• Accuracy: ± 0.3 % of span
• Process temp: -10 °C to +100 °C (with short excursions to +135 °C)
• Guardian protection: IP69 for washdown conditions
• Optional communication: IO-Link, analog 4-20 mA

It is available in both absolute and gauge pressure versions, depending on what you need to measure.

Absolute Pressure vs. Gauge Pressure (in general)

Absolute Pressure

• Definition: Measured relative to a perfect vacuum (zero reference is no pressure at all).
• Sensor reference: One side of the sensing element is sealed to a vacuum.
• Use cases: Required when true total pressure matters — e.g., in vacuum processes, sealed systems, or when atmospheric pressure changes affect process conditions.
• Result: Absolute pressure = gauge pressure + local atmospheric pressure.

Gauge Pressure

• Definition: Measured relative to ambient atmospheric pressure (zero is atmospheric pressure).
• Sensor reference: One side of the sensor is open to or references the surrounding atmosphere.
• Use cases: Most industrial pressure measurements such as pipes, tanks, pumps, compressors — because what matters is the pressure above atmospheric.
• Result: Gauge pressure = absolute pressure − atmospheric pressure.

How the Cerabar PMP23 Handles These

The Cerabar PMP23 transmitter can be configured and built either as:

1. Gauge Pressure Version

• Measures pressure relative to atmospheric pressure.
• Best for typical process control and fluid handling tasks where you care about pressure above ambient.
• Zero output corresponds to atmospheric pressure (0 barg).

2. Absolute Pressure Version

• Measures true pressure relative to vacuum.
• Useful when atmospheric variations matter or when measuring vacuum/pressures below atmospheric.
• Zero output corresponds to complete vacuum (0 bara).

The same model family supports both types — you choose at order or configuration what reference the transmitter uses.

Practical Differences

Why It Matters

• Process control: Gauge pressure is usually enough for valves, pumps, and regulators.
• Vacuum and sealed systems: Absolute pressure avoids errors due to atmospheric changes.
• Hygienic industries: PMP23 supports both depending on the application needs without changing the core sensor design.