Endress+Hauser Deltabar Differential Pressure Transmitter Series Overview
The Endress+Hauser Deltabar series comprises high-performance differential pressure transmitters designed for pressure, level, and flow measurements. The models PMD50, PMD55B, PMD75B, and PMD78B cater to a broad spectrum of applications—from basic monitoring tasks to highly demanding process conditions. They are distinguished by their robust sensor technology, advanced diagnostics, and user-friendly operation.
| Model | Core Positioning | Typical Applications |
| PMD50 | Basic model for standard applications | Differential pressure, level, and flow monitoring for general liquids and gases |
| PMD55B | Next-generation general-purpose model; cost-effective and practical | High-accuracy differential pressure, level, and flow measurement for liquids and gases |
| PMD75B | High-performance model with advanced diagnostics | Complex process applications; capable of detecting process abnormalities (e.g., impulse line blockage) |
| PMD78B | Expert model for harsh and extreme-temperature conditions | Equipped with remote seals; suitable for high process temperatures, corrosive media, or processes requiring isolation |
Key Performance Specifications Comparison
| Parameter | PMD50 | PMD55B | PMD75B | PMD78B |
| Measuring Principle | Piezoresistive, metallic diaphragm | Piezoresistive, metallic diaphragm | Piezoresistive, metallic diaphragm | Piezoresistive, metallic diaphragm |
| Max. Measuring Range | 40 bar (600 psi) | 40 bar (600 psi) | DP: 40 bar (600 psi) Gauge/Abs: up to 250 bar |
40 bar (600 psi) |
| Reference Accuracy | Up to 0.055 % | Up to 0.055 % | Up to 0.035 % | Up to 0.075 % |
| Process Temperature | -40…+110 °C | -40…+110 °C | -40…+110 °C | -70…+400 °C (with diaphragm seal) |
| Max. Static Pressure | 160 bar (2320 psi) | 250 bar (3750 psi) | 420 bar (6300 psi) | 160 bar (2400 psi) |
| Turndown Ratio | 20:1 | 100:1 | Data Missing | 100:1 |
| Long-term Stability | 0.1 % URL/year | 0.05 % URL/year | 0.025 % URL/year | 0.025 % URL/year |
| Heartbeat Technology | Not supported | Not supported | Supported | Supported |
As indicated in the table, the PMD75B and PMD78B feature Heartbeat Technology for comprehensive self-diagnostics and in-situ verification, whereas the PMD55B and PMD50 focus on delivering reliable and economical solutions for routine applications.
Shared Features & Core Technologies
All models incorporate the advanced design principles of the Deltabar family:
Smart Operation & Connectivity: The next-generation models (PMD55B, PMD75B, PMD78B) support remote operation via the SmartBlue App and Bluetooth, which greatly simplifies commissioning and maintenance in hard-to-reach areas. Intuitive setup wizards help minimize operational errors.
Versatile Communication & Certifications: All models support 4-20 mA HART protocol, while newer versions also offer PROFINET over Ethernet-APL. They generally feature SIL functional safety certification and provide a wide range of explosion-proof approvals (ATEX, IECEx, etc.) as well as NACE corrosion resistance certification.
Flexible Material Selection: To accommodate various media, wetted parts can be fabricated from highly corrosion-resistant materials, including 316L, Alloy C (Hastelloy), Gold, and Tantalum.
Summary: Selecting the Right Model
| If you need… | Recommended Model |
| A cost-effective solution for basic pressure monitoring | PMD50 |
| A versatile, next-generation transmitter for general use | PMD55B |
| High accuracy with self-diagnostics for complex processes | PMD75B |
| Performance under extreme temperatures or with aggressive media (remote seal required) | PMD78B |
Endress+Hauser Deltabar Differential Pressure Transmitter Series – Product Description
The Deltabar series is Endress+Hauser’s high-performance differential pressure transmitter product line, utilizing piezoresistive metallic diaphragm sensor technology for a wide range of differential pressure, level, and flow measurement applications. The four models—PMD50, PMD55B, PMD75B, and PMD78B—are structured according to Endress+Hauser’s FLEX product selection philosophy, covering the complete spectrum from fundamental to expert-level solutions, enabling users to select the most suitable instrument for their specific process conditions.
PMD50 – Fundamental
The PMD50 is a basic differential pressure transmitter optimized for standard applications. Equipped with a metallic diaphragm sensor, it is suitable for differential pressure monitoring of liquids and gases, with a maximum measuring range of 40 bar (600 psi) and reference accuracy up to 0.055%. The device features an intuitive setup wizard for rapid commissioning and is developed in accordance with IEC 61508 functional safety standards, offering SIL certification. Key wetted parts are available in 316L, Alloy C, or Gold materials. Process temperature ranges from -40 to 110°C (up to 400°C with diaphragm seal), with a maximum static pressure of 160 bar (2320 psi), turndown ratio of 20:1, and long-term stability of 0.1% URL/year.
PMD55B – Lean
The PMD55B is a next-generation Deltabar transmitter positioned as a versatile, cost-effective general-purpose instrument. It supports both local and remote operation via the SmartBlue App and Bluetooth connectivity, enabling mobile device control for significantly improved service efficiency. The software includes an intuitive setup wizard that guides users through instrument configuration and functional safety testing, effectively reducing the risk of operating errors. Measuring range up to 40 bar (600 psi), with Platinum-class accuracy of ±0.055%, maximum static pressure of 250 bar (3750 psi), turndown ratio of 100:1, and long-term stability of 0.05% URL/year. Wetted parts are available in 316L and Alloy C materials, process temperature range from -40 to 110°C, with support for 4-20mA HART and PROFINET over Ethernet-APL communication, and SIL certification.
PMD75B – Extended
The PMD75B is a high-performance differential pressure transmitter integrated with Heartbeat Technology, positioned to optimize process operations through innovative diagnostic capabilities. This technology enables in-situ verification and self-monitoring without process interruption, and can detect process abnormalities such as impulse line blockage. Device status is intuitively indicated by the display color—switching from green to red when a diagnostic event occurs. Differential pressure range up to 40 bar (600 psi), gauge/absolute pressure range up to 250 bar (3750 psi), with Platinum-class accuracy of ±0.035% and maximum static pressure of 420 bar (6300 psi). Key wetted parts are available in a variety of corrosion-resistant materials including 316L, Alloy C, Tantalum, Monel, or Gold. Also supports SmartBlue App Bluetooth remote operation and SIL functional safety certification.
PMD78B – Xpert
The PMD78B is an expert-level differential pressure transmitter designed for harsh process conditions and extreme-temperature measurement requirements. Equipped with diaphragm seals and capillary tubes, it is ideal for high process temperatures, corrosive media, or applications requiring process isolation. Process temperature range spans from -70 to +400°C (with diaphragm seal), with a maximum measuring range of 40 bar (600 psi) and static pressure of 160 bar (2400 psi). This model also features Heartbeat Technology for device health verification and abnormality detection during process operation, along with SmartBlue App Bluetooth remote operation. Platinum-class accuracy up to ±0.075%, turndown ratio of 100:1, and long-term stability of 0.025% URL/year. The TempC diaphragm technology effectively minimizes the impact of ambient and process temperature variations on measurement accuracy.
All four models share the core design principles of the Deltabar family, including intuitive setup wizards, flexible material selection, a comprehensive range of explosion-proof certifications, and SIL functional safety certification. Users can select the appropriate model based on application complexity, accuracy requirements, and the severity of process conditions.