Proline Promass 83E/F/O Operation Manual - FMC Technologies

Proline Promass 83Commissioning6.5.2 Density adjustmentIt is advisable to perform a density adjustment when optimum measuring accuracy is required forcalculating density dependent values. The application may require a 1-point or 2-point densityadjustment.1-point density adjustment (with one fluid):This type of density adjustment is necessary under the following circumstances:• The sensor does not measure exactly the density value that the user expects on the basis oflaboratory analyses.• The fluid properties are outside the measuring points set at the factory, or the reference operatingconditions used to calibrate the measuring device.• The system is used exclusively to measure a fluid’s density which must be registered to a highdegree of accuracy under constant conditions.Example: Brix density measurement for apple juice.2-point density adjustment (with two fluids):This type of adjustment is always to be carried out if the measuring tubes have been mechanicallyaltered by, e.g. material buildup, abrasion or corrosion. In such cases, the resonant frequency of themeasuring tubes has been affected by these factors and is no longer compatible with the calibrationdata set at the factory. The 2-point density adjustment takes these mechanically-based changes intoaccount and calculates new, adjusted calibration data."Caution!Performing a 1-point or 2-point density adjustment• Onsite density adjustment can be performed only if the user has detailed knowledge of the fluiddensity, obtained for example from detailed laboratory analyses.• The target density value specified in this way must not deviate from the measured fluid densityby more than ±10%.• An error in defining the target density affects all calculated density and volume functions.• The 2-point density adjustment is only possible if both target density values are different fromeach other by at least 0.2 kg/l. Otherwise the error message #731 (adjustment is not possible)appears in the "Diag. - Act. Sys. Condition" parameter.• Density adjustment changes the factory density calibration values or the calibration values set bythe service technician.• The functions outlined in the following instructions are described in detail in the "Description ofDevice Functions" manual.1. Fill the sensor with fluid. Make sure that the measuring tubes are completely filled and thatliquids are free of gas bubbles.2. Wait until the temperature difference between fluid and measuring tube has equalized. Thetime you have to wait for equalization depends on the fluid and the temperature level.O S3. Using the local display, select the SETPOINT DENSITY Ffunctionin the function matrix andperform density adjustment as follows:FunctionNo.Function name Setting to be selected ( O or S )(to next function with F )6482 DENSITY ADJUST MODE Use P to select a 1- or 2-point adjustment.! Note!When you press P you are automatically prompted to enter the accesscode if the function matrix is still disabled. Enter the code.6483 DENSITY SET VALUE 1 Use P to enter the target density of the first fluid and press F to savethis value (input range = actual density value ±10%).Issue/Rev. 0.2 (12/12) MN0M022 • Page 79