EES-401 Series Ultrasonic Energy Meter
Revision: 3.0.1
Page 20 of 90
6
Operating Instructions
6.1
System Normal Identification
Press the
keys. If the letter "*R" displays on the screen, it indicates system normal.
If the letter "G" is displayed, it indicates that system is adjusting the signal gain prior to the measurement. Also, it
means system normal. Only when the adjustment takes too long (
＞
2min) without stopping, can system be
identified as abnormal.
Letter "I" indicates no signal is being detected. Check the transducer wiring connections are correct, the
transducers are installed firmly, etc.
For further information, please refer to "Error Diagnosis".
6.2
Low Flow Cutoff Value
The data in M41 is Low Flow Cutoff Value. If the flow rate falls below the low flow cutoff value, the flow
indication is driven to zero. This function can prevent the flow meter from displaying flow as "0"after a pump was
shut down, but there is still liquid movement in the pipe, which will result in cumulative error. Generally, 0.01m/s
is recommended to enter as the low flow cutoff point.
The low flow cutoff value has no relation to the measurement results once the velocity increases over the low flow
cutoff value.
6.3
Zero Settings
Once zero flow occurs, a zero point may indicate on each measuring instrument, but the displayed measuring
value is not equal to "0", this value indicates "Zero". To any measuring instrument, the smaller the "Zero" is, the
better the quality is. Conversely, if the Zero is too big, that indicates the quality of the instrument is poor.
If the zero set point is not at true zero flow, a measurement difference may occur. The smaller the physical
measurement capacity is, the larger the measurement difference from the zero point will exist. Only when zero
point reduced to a definite degree, as compared with the physical measurement capacity, can the measuring
difference from zero point be ignored.
For an ultrasonic Energy Meter, the measurement error from zero point cannot be ignored under low flow
conditions. It is necessary to perform a static zero set calibration to improve low flow measurement accuracy.
Press Window M42 to set the Zero, press
first, and then wait the readings display is finished. If this is
carried out with flow, the flow will be displayed as "0", M43 can help to restore settings.
6.4
Scale Factor
Scale factor refers to the ratio between "actual value" and "reading value". For example, when the measurement is
2.00, and it is indicated as 1.98 on the instrument, the scale factor reading is 2/1.98. This means that the best scale
factor constant is 1. However, it is difficult to keep the scale factor as "1" on the instrument especially in batch
productions. The difference is called "consistency".
During operation, there still exists possible difference in pipe parameters, etc. The "scale factor" may be necessary
when used on different pipes. Thus, scale factor calibration is specially designed for calibrating the differences
that result from application on different pipes. The scale factor entered must be one that results from actual flow
calibration. The scale factor can be input in Window M45.
6.5
System Lock
System lock is intended to prevent operation error due to tampering by unauthorized personnel.
Press the
keys, move
or
key to select "Lock", press the
key, enter a 1 ~ 4 numerically long password, and then press the
key to confirm.