Calibrating an ultrasonic level transmitter involves the following steps:
- Gather the necessary equipment: Arrange a calibration device, such as a reference tank or a calibration simulator, as well as a multimeter or a handheld communicator with HART or Foundation Fieldbus capabilities, depending on the communication protocol used by your transmitter.
- Ensure safety: Follow appropriate safety procedures, such as isolating the transmitter from the process and verifying that the area is safe for calibration activities.
- Set up the calibration equipment: If you’re using a reference tank, fill it with a known level of liquid that corresponds to a specific measurement. If you have a calibration simulator, set it to generate the desired signal corresponding to the desired level.
- Connect the calibration equipment: Connect the calibration device to the ultrasonic level transmitter using the appropriate connections. This may involve disconnecting the process connection to attach the calibration device.
- Access the transmitter’s configuration: Use the appropriate software or handheld communicator to access the configuration settings of the ultrasonic level transmitter. This will allow you to make adjustments during the calibration process.
- Initiate calibration mode: Enable the calibration mode on the transmitter. This mode is typically available in the configuration settings and allows you to make adjustments without affecting the normal operation of the transmitter.
- Adjust zero level: With the calibration device set to the lowest level, adjust the zero level of the transmitter to match the reference signal or measurement. This ensures that the transmitter accurately represents the empty or lowest level condition.
- Adjust span level: With the calibration device set to the highest level, adjust the span level of the transmitter to match the reference signal or measurement. This ensures that the transmitter accurately represents the full or highest level condition.
- Verify intermediate levels: Check the accuracy of the transmitter at selected intermediate levels to ensure that it provides accurate measurements throughout the range. Adjustments may be needed if any discrepancies are found.
- Finalize calibration: Once you have verified the accuracy at multiple levels, exit the calibration mode and save the configuration settings. Reconnect the process connection if it was disconnected during the calibration.
- Perform validation: After completing the calibration, it’s important to validate the transmitter’s performance by comparing its readings against known levels or measurements in the process. This step ensures that the transmitter is functioning within acceptable tolerances.
Remember to consult the manufacturer’s documentation and specific guidelines for your ultrasonic level transmitter model, as the calibration process may vary slightly depending on the device. Additionally, it’s always recommended to follow any safety procedures and regulations relevant to your industry.