The importance of level measurement cannot be overstated. Incorrect or inappropriate measurements can cause levels in vessels to be excessively higher or lower than their measured values. Vessels operating at incorrect intermediate levels can result in poor operating conditions and affect the accounting of material.
The level of a liquid in a vessel can be measured directly or inferentially. Examples of direct level measurement include float, magnetostrictive, retracting, capacitance, radar, ultrasonic and laser level measurement technologies. Weight and differential pressure technology measure level inferentially. All have problems that can potentially affect the level measurement. Differential pressure level measurement technology infers liquid level by measuring the pressure generated by the liquid in the vessel.
For example, a water level that is 1000 millimeters above the centerline of a differential pressure transmitter diaphragm will generate a pressure of 1000 millimeters of water column (1000 mmWC) at the diaphragm. Similarly, a level of 500 millimeters will generate 500 mmWC. Calibrating this differential pressure transmitter for 0 to 1000 mmWC will allow it to measure water levels of 0 to 1000 millimeters. Using the available information properly is another potential problem. Some years ago, distributed control system inputs were incorrectly configured to correspond to the maximum transmitter spans. Aside from using incorrect values, the levels should have been expressed in percent. Using absolute level measurement units such as inches, feet, millimeters or meters increases the potential for error because operators must remember the height of each vessel to put the level measurement in context with the vessel. This can easily become overwhelming and cause operator errors because plants often have hundreds of vessels.
Differential pressure measurement is a workhorse of industrial level measurement that is been used for decades and will continue to be used for decades to come.
This may be a good place to introduce yourself and your site or include some credits.
Search
Automation Training
Our foundation-to-advanced automation course training covers end-to-end industrial workflows used in modern plants. Learners practice the full cycle from basic circuits to commissioning and maintenance with hands-on labs, project-based fault finding, SOP creation, and documentation exposure (URS, FDS, FAT/SAT).
PLC Training
This PLC training builds controller fundamentals with ladder, FBD, and ST, including I/O wiring, PID tuning, diagnostics, and version control practices on live rigs.
SCADA Training
Our SCADA course covers tag databases, HMI graphics, historian/trends, alarm rationalization, redundancy, user security, backups, and deployment aligned to plant standards.
Panel Designing
This panel design course teaches standards-compliant MCC/PLC panel engineering, SLD/GA/wiring docs, device selection, heat-load, testing, and FAT.
BMS & Security
BMS training focuses on HVAC/lighting/utilities automation; CCTV & security covers design, storage, networking, and analytics.
IIoT
The Industrial IoT diploma spans sensors-to-dashboard pipelines: MQTT/OPC UA, gateways, historians, alerts/KPIs, and predictive maintenance basics.
