Manual Operation
43
4.2.1 Meter
Mode
A coriolis mass flow meter measures the mass flow and the density and can calculate the volume flow.
For avoiding strange effects with the total values when changing the dimensions, the TCE8000 can be set up as a
mass flow OR a volume flow meter.
When set up as mass flow meter, only mass and mass flow engineering units can be selected, when set up as
volume flow meter, only volume and volume flow engineering units can be selected.
For changing the meter mode refer to chapter 4.5.6.1.
4.2.2 Offset
Calibration
In contrast to a PD meter, a coriolis mass flow meter has no “natural” zero. At no flow the measured time shift is
nearly zero, but not exactly. The offset calibration determines this offset and corrects the measured value
correspondingly.
As the offset depends slightly upon the temperature, the density of the medium and the operating pressure, it is
strongly recommended to make the offset procedure under working conditions, i.e. with the medium to be
measured and at operating pressure and temperature.
For making the offset calibration refer to chapter 4.4 and 4.5.3.
4.2.3 Flow
filter
The rough data of a mass flow meter are relative noisy. For having a stable reading a filtering of the calculated
flow is required.
The filters in the TCE8000 are set via the time constant t. The time constant is the time the output needs after a
jump from x to 0 to go to x/e = x/2.72. A higher time constant means more stable reading but also a slower
reaction to changing flows.
A rough relation between the time and the filtered flow value after a jump is
Elapsed time
Remaining error (% of the step)
1 * t
30
2 * t
10
3 * t
3
4 * t
1
A linear filter as it is realized in the TCE8000 electronics just delays the flow reading and consequently the total.
Independent of the slope (fast or slow) of the rising and falling flow, the error of the internally calculated total and
at the frequency output cancel out, if the flow rises from zero (or any other value) and later goes back to the
starting value. For getting a correct total via the display or the frequency output, it is just necessary to wait long
enough after the flow is switched off.
For best results the TCE8000 electronics provide 2 filters.
The FLOW FILTER filters the mass flow before calculating other parameters like volume flow, total or the
frequency and current outputs. For normal applications a moderate filtering with t = 1s is recommended.
The DISPLAY FILTER filters the flow display additionally to the FLOW FILTER. It does not affect any other
parameter or any of the outputs. The default setting is t = 1s.
If the flow is fast changing or sometimes makes a jump and the outputs have to react as fast as possible, set
FLOW FILTER to t < 1s. If nevertheless the flow display has to be stable for better readability, the DISPLAY
FILTER can be increased.
For setting up the FLOW FILTER refer to chapter 4.5.6.2, for the DISPLAY FILTER to chapter 4.5.4.1.
Summary of Contents for TRICOR TCE80 -E Series
Page 1: ...Certified according to DIN ISO 9001 Manual TRICOR Coriolis Mass Flow Meter ...
Page 2: ...SW Version Main V2 0x Display V2 0x Manual Revision 2 1 ...
Page 93: ...Listings 93 Fig 26 Dimensions TCE8000 E except A Fig 27 Dimensions TCE8000 E A ...
Page 98: ...Contact Copyright KEM Subject to change without notice ES Rev 002 23 01 2012 ...
