Temperature Variations:
Impact: Temperature fluctuations can significantly impact the accuracy of a differential pressure transmitter.
Process Media Temperature: Changes in the temperature of the fluid being measured can affect its density and viscosity, altering the pressure reading.
Ambient Temperature: Variations in ambient temperature can affect the internal components of the transmitter, causing shifts in calibration and zero points.
Mitigation:
Temperature Compensation: Select low differential pressure transmitters with built-in temperature compensation mechanisms to minimize the effects of temperature changes.
Temperature Stabilization: Maintain a stable ambient temperature around the transmitter whenever possible.
Thermal Insulation: Use thermal insulation to minimize temperature fluctuations around the transmitter and process connections.
Static Pressure Effects:
Impact: Static pressure is the average pressure acting on both sides of the differential pressure sensor.
High static pressure can affect the sensor's diaphragm, leading to non-linearity and reduced accuracy.
Variations in static pressure can also cause zero shifts in the low differential pressure transmitter output.
Mitigation:
Static Pressure Compensation: Choose transmitters with built-in static pressure compensation features.
Proper Installation: Install the transmitter in a location with minimal static pressure variations.
Regular Calibration: Perform regular calibration checks to account for any static pressure effects.
Process Media Effects:
Impact: The properties of the process fluid (e.g., density, viscosity, corrosivity) can directly affect the transmitter's accuracy.
Corrosive fluids can damage the sensor diaphragm or other internal components.
High-viscosity fluids can impede the movement of the diaphragm, leading to inaccurate readings.
Mitigation:
Material Selection: Choose low differential pressure transmitters with materials compatible with the specific process fluid (e.g., stainless steel, Hastelloy).
Flushing: Install flushing systems to prevent solids buildup and maintain clean sensor surfaces.
Regular Inspection: Regularly inspect the transmitter for signs of corrosion or other damage.
Vibration and Shock:
Impact: Vibrations and shocks can cause mechanical stress on the sensor diaphragm, leading to:
Zero shifts: Permanent or temporary changes in the zero point of the transmitter.
Noise in the output signal: Increased noise levels, making it difficult to obtain accurate readings.
Sensor damage: In severe cases, vibrations can cause physical damage to the sensor.
Mitigation:
Vibration Isolation: Use vibration isolators or flexible couplings to isolate the transmitter from external vibrations.
Rigid Mounting: Ensure the transmitter is securely mounted to a stable structure to minimize the impact of vibrations.
Shock Absorbers: Install shock absorbers in the process piping to reduce the impact of pressure surges.
Long-Term Stability:
Impact: Over time, the performance of the transmitter may degrade due to factors such as:
Sensor drift: Gradual changes in the sensor's characteristics, leading to inaccuracies in measurements.
Electronic component aging: The aging of electronic components within the transmitter can affect its accuracy and reliability.
By carefully considering and addressing these factors, it is possible to minimize the impact on the accuracy of low differential pressure transmitters and ensure reliable and accurate process measurements.