A Guide to Calibrating Submersible Level Transmitters

Submersible level transmitters are essential tools used in various industries to measure liquid levels within tanks, reservoirs, wells, and other liquid storage systems. Accurate calibration of these transmitters ensures reliable and precise level readings, preventing costly inaccuracies and potentially hazardous situations. In this comprehensive guide, we will delve into the process of calibrating submersible level transmitters, highlighting the necessary steps, tools, and techniques to achieve optimal performance.

I. Introduction to Submersible Level Transmitters

II. Understanding the Calibration Process

III. Essential Tools for Calibration

IV. Step-by-Step Calibration Procedure

V. Troubleshooting and Maintenance Tips

I. Introduction to Submersible Level Transmitters

Before delving into the calibration process, it is crucial to understand the basic functions and components of submersible level transmitters. These devices are typically composed of a sensing element, housing, diaphragm, and various electronic components.

Submersible level transmitters are designed to be immersed directly in the liquid being measured, providing continuous level measurements. They work on the principle of hydrostatic pressure, where the pressure exerted by the liquid column above the sensing element determines the liquid level.

II. Understanding the Calibration Process

Calibration is the process of adjusting and aligning the submersible level transmitter to ensure accurate readings. It involves comparing the device's measurement output to a known reference or standard. By calibrating the transmitter, you can eliminate any systematic errors and improve overall measurement accuracy.

III. Essential Tools for Calibration

To successfully calibrate a submersible level transmitter, several tools and equipment are necessary. Here are some essential items you'll need:

1. Differential Pressure Calibrator: A calibrator that can generate precise pressure differentials is essential for accurate calibration. Ensure it covers the required ranges of your submersible level transmitter.

2. Pressure/Vacuum Source: This device is used to apply and control pressure or vacuum during the calibration process. It should be capable of generating the required pressure range.

3. Multimeter: A digital multimeter is necessary to measure the output signals and troubleshoot any electrical issues during calibration.

4. HART Communicator: If your submersible level transmitter supports HART communication, a HART communicator enables you to interact with the device's digital communication interface, making calibration and adjustments more efficient.

5. Calibration Certificate: It is recommended to use a traceable calibration certificate to ensure accuracy. The certificate provides information on the transmitter's calibration history and the reference standard used.

IV. Step-by-Step Calibration Procedure

1. Preparation:

a. Ensure the submersible level transmitter is clean and free from any obstructions or debris.

b. Consult the manufacturer's guidelines and documentation for specific calibration procedures.

c. As a safety precaution, ensure that appropriate isolation measures are implemented to prevent accidents.

2. Mounting the Submersible Level Transmitter:

a. Install the transmitter in the liquid storage system, ensuring proper sealing and attachment to prevent leaks.

b. Ensure the transmitter is positioned at the desired level range and secured in place.

3. Initial Verification:

a. Connect the transmitter to a HART communicator or multimeter and verify the electrical connectivity.

b. Confirm that the transmitter is receiving power and that the output signals are within the expected range.

4. Establishing Calibration Points:

a. Identify the calibration points based on the desired level range.

b. Select at least three points, including the minimum, maximum, and one intermediate level.

c. It is recommended to choose points within 20-80% of the transmitter's measurement range to ensure accurate results.

5. Conducting the Calibration:

a. Apply the known pressure or vacuum to the transmitter and record the corresponding output signal.

b. Compare the measured output signal with the reference value and note any discrepancies.

c. Adjust the transmitter if necessary, following the manufacturer's instructions and considering the reference standard used.

6. Final Verification:

a. After adjusting the transmitter, verify all calibration points again to ensure accuracy and reliability.

b. Document the calibration results, including any adjustments made, deviations found, and calibration certificate information.

V. Troubleshooting and Maintenance Tips

To maintain the optimal performance of your submersible level transmitter, consider the following tips:

1. Regularly inspect the transmitter for any physical damage or corrosion.

2. Perform periodic verification of calibration to detect any drift or deviation.

3. Clean the transmitter regularly to remove any build-up or contaminants that may affect its performance.

4. Address any electrical or wiring issues promptly to ensure accurate signal transmission.

5. Follow recommended maintenance schedules provided by the manufacturer.

By following this comprehensive guide, you can calibrate your submersible level transmitters with confidence, ensuring accurate and reliable level measurement readings. Implementing regular calibration and maintenance procedures will not only prevent measurement errors but also extend the lifespan of your transmitters, providing longevity and cost-effectiveness to your operations.