Siemens SITRANS LUT400 - Verifying the Ma Range; Volume; Readings; Vessel Shape and Dimensions

General Operation
7.5 Volume
SITRANS LUT400
Operating Instructions, 07/2019, A5E33329501-AC
95
Note
If default values (4 and 20 mA) are used for the minimum and maximum mA limits, the mA
output (shown in
Current Output Value (2.5.8.) (Page 179)) will remain at the set mA limit,
even if the level reading falls below/rises above the mA setpoints.
7.4.2 Verifying the mA range
Checks that the external device can track the entire 4 to 20 mA range sent by the SITRANS
LUT400. Follow the steps below if actual mA readings differ between the LUT400 (shown in
Current Output Value (2.5.8.) (Page 179)) and an external device (such as a PLC).
1. To test the loop current, set Current Output Function (2.5.2.) (Page 176) to Manual, then
set the value to use in Manual Value (2.5.7.) (Page 179).
2. Check that the external device displays the same mA reading as the mA value set above.
3. If external device reading differs from the set manual value on the LUT400, adjust the
reading on the external device to match the reading on the LUT400.
7.5 Volume
Volume is used in two situations:
1. Calculate and display volume instead of level.
2. Calculate pumped volume to accomplish the following:
● Totalize the volume of material that is pumped out of the wet well.
7.5.1 Readings
When using volume, readings are given in units specified in Volume Units (2.6.2.)
(Page 181).
7.5.2 Vessel Shape and Dimensions
There are many common vessel shapes to select from. (See Vessel Shape (2.6.1.)
(Page 180). If possible, use one of these.) Each vessel shape uses the Low Calibration Point
(2.2.1.) (Page 171) in its calculations of volume.
Some vessel shapes also require extra dimensions to calculate the volume. Do not estimate
these values. They must be correct to ensure the accuracy of your volume calculations.