what is the best instrument out there to measure liquid in a tank
The best type of level measurement will depend on several factors
- The Precision required
If the level is measure for accounting purposes, a tape type unit maybe the best, otherwise you could use HTG or DP type.
- The process conditions
If the level to be measured has to many fumes or vapors on top of the level, then radar may no be the best.
If the level has interfaces of different liquids, then you may need to use HTG or Capacitance but not radar.
If the level has high viscosity, plugs up, or maybe corrosive then you may opt for an external displacer type.
So here are some of the options.
Tank level measurement all depends on as an early comrade mentioned accuracy. However there are other factors to consider which would be repeatability and even cost. In given process applications the probe or type of level measurement system used would be the difference between continued and sustained operation or a regular change out, replacement, recalibration or re installation. One type of level instrument proven to offer durability and a reasonable assurance of accuracy is ultrasonic level measurement. Not too complicated of a theory and once correctly calibrated with correct measurements for empty, span and blanking distances can provide sustained and accurate data for level measurement.