Stepping motor diaphragm metering pump FEM 1.02 / FEM 1.09
Technical data
KNF Flodos AG BA_FEM1-02_1-09_EN_07_157639.docx
Translation of Original Operating and Installation Instructions
8
Accuracy/reproducibility
The accuracy of the calibrated metering pump is appropriately characterised
by the maximum absolute error A (dependent on the nominal value) and the
maximum relative error B (dependent on the setting value):
max. inaccuracy ≤ (A + B)
FEM 1.02
Error
Value
Absolute error A
≤ ±0.1% of nominal value
Relative error B
≤ ±1.0% of setting value
Tab. 10
FEM 1.09
Error
Value
Absolute error A
≤ ±0.1% of nominal value
Relative error B
≤ ±1.0% of setting value
Tab. 11
Example: FEM 1.09; the nominal value for stroke volume is 500 µl
For a setting of 260 µl, the accuracy should therefore be within the following
error limits:
Inaccuracy
≤ (±0.1% x 500 µl) + (±1.0% x 260 µl)
≤ (±0.5 µl) + (±2.6 µl)
≤ ±3.1 µl
≈ ±1.2% of setting value
Under constant environmental conditions the pump achieves a reproducibility
of less than ±1%.
Greater inaccuracies may occur for fluids with a viscosity of >
150 cSt or with a tendency to outgas. Appropriate adjustments
may be made during calibration.
The accuracy of the pump is ultimately a matter of the meas-
urement and pumping system and the parameters with which
the pump is operated. The hose types used and the design of
the hose end at the pressure side play an important part in
precise metering.
FEM 1.02 ... SM-2 and FEM 1.09 ... SM-2 are not calibrated in the factory.
The pump must be calibrated electronically via the controller in the customer
system.
The flow rate may differ from the calibrated value in some applications. This is
influenced by the following factors: type of medium, its viscosity, density and
temperature, pressure and installation type (e.g. cross-section constrictions).
For accurate metering it is therefore recommended that the metering pump be
calibrated.
Accuracy
Reproducibility
Factory calibration
Calibration
