VEGADIF 85 Differential Pressure Transmitter Overview
VEGADIF 85 is a high-performance differential pressure transmitter used for differential pressure, level, flow, and density measurement. It uses a metallic diaphragm sensor, features high overload capability and long-term stability, and is suitable for industrial applications such as chemical, petrochemical, pharmaceutical, and water treatment. This article provides the official Chinese manual download and explains selection, installation, and commissioning.
Click to download: VEGADIF 85 Chinese Manual.pdf
Measurement Principle and Core Advantages
VEGADIF 85 is based on piezoresistive or capacitive differential pressure measurement principles and converts the pressure difference between the two sides into a standard electrical signal output. Its core advantages lie in high accuracy, wide turndown ratio, and strong overload resistance, enabling it to handle complex working conditions.
- High accuracy: Reference accuracy can reach ±0.075%, meeting the needs of custody transfer and process control.
- Wide turndown ratio: Turndown ratio can reach 100:1, reducing inventory models.
- Overload protection: Strong single-side overload capability prevents damage from misoperation.
- Multiple outputs: Supports 4-20mA HART, Profibus PA, and Foundation Fieldbus.
Key Technical Parameters
The following table lists typical technical parameters of VEGADIF 85 for selection reference. Actual parameters are subject to the latest Chinese manual.
| Parameter | Typical Value/Range |
|---|---|
| Measuring range | 0~0.1 kPa to 0~40 MPa |
| Reference accuracy | ±0.075% URL |
| Turndown ratio | 100:1 |
| Output signal | 4-20mA HART / Profibus PA / FF |
| Process temperature | -40~+120°C (higher optional) |
| Ambient temperature | -40~+85°C |
| Protection class | IP66/IP67 |
| Process connection | Thread, flange, hygienic type |
Installation and Commissioning Steps
Correct installation and commissioning are key to ensuring measurement accuracy. The following steps apply to conventional differential pressure measurement applications.
- Installation location: Avoid installation in locations with high vibration, severe temperature changes, or accumulation of corrosive gases.
- Impulse line connection: Ensure the high and low pressure sides correspond correctly, and the impulse line slope should be no less than 1:10 to prevent liquid or gas accumulation.
- Electrical wiring: Connect the power supply and signal lines according to the wiring diagram in the manual, and note that the shield layer should be grounded at one end.
- Zero calibration: Perform zero adjustment under no differential pressure to eliminate the effect of installation stress.
- Range setting: Set the upper and lower limits via a HART communicator or local buttons, and perform elevation or suppression if necessary.
- Verification test: Apply standard pressure and check output linearity and error.
Typical Application Scenarios
VEGADIF 85 is widely used in the following scenarios. During selection, the medium characteristics and process conditions must be considered.
- Level measurement: Level in closed vessels, with or without a seal pot or direct installation.
- Flow measurement: Used with throttling devices such as orifice plates and averaging pitot tubes to measure gas, steam, or liquid flow.
- Filter differential pressure: Monitor filter blockage status and promptly indicate maintenance needs.
- Density measurement: Infer medium density from differential pressure under specific conditions.
Selection Precautions and Common Issues
During selection, process connection, diaphragm material, fill fluid, and explosion-proof certification must be confirmed. Common issues include zero drift, impulse line blockage, and signal interference, most of which can be avoided through proper installation and regular maintenance.
- Diaphragm material: Select 316L, Hastelloy, tantalum, etc., according to medium corrosiveness.
- Fill fluid: For high-temperature or vacuum applications, high-temperature silicone oil or inert fill fluid should be selected.
- Explosion-proof certification: For hazardous areas, intrinsically safe or flameproof types should be selected.
- Troubleshooting: First check whether the impulse line is blocked, then verify the power supply and signal loop.
The above content is compiled based on the VEGADIF 85 Chinese manual. For complete details, please download the PDF document for reference.