Full tank threshold
Note
By default, the Full Tank Threshold Offset value is 0 (function is not used). Do not use this
function unless you are qualified.
The Full Tank threshold is related to the Reference Threshold, and can be used for
detecting that the tank is full.
The given offset value determines the gap between the
Reference threshold and the Full Tank threshold. The transmitter considers the tank full
when the amplitude of the Reference Peak has dropped to a value between the two
threshold values.
If the amplitude of the Reference peak is below the Full Tank Threshold (negative
amplitude of the Reference peak), the tank is not considered full.
By default, this value is 0 (function is not used). This is because highly contaminated or
condensed tank-seals, and turbulent or boiling surfaces, which can cause splashing, may
cause function to be triggered.
Probe end threshold
Threshold to filter out noise in the echo curve for detection of the Probe End peak. The
probe end peak is a fairly strong positive or negative echo (depending on probe type) that
is present at the probe end when tank is empty.
Guidelines for setting the amplitude thresholds
Normally, the amplitude thresholds are automatically set by the transmitter, and no
manual settings are needed. However, due to the properties of the product, it may in rare
cases be necessary to adjust the amplitude thresholds for optimum measurement
performance.
Guidelines for setting the surface threshold
Before changing the Surface Threshold, make sure the product level is at least 20 in. (0.5
m) from the lower side of the device flange.
•
Surface Thresholds should never be set to values less than:
—
700 mV at distance 0-20 ft. (0-6 m) from the upper reference point.
—
500 mV at distance more than 20 ft. (6 m) from the upper reference point.
•
Set the Surface Threshold to about
⅓
of the weakest surface echo amplitude in the
measuring range.
(7)
The full tank threshold has no impact on the large coaxial probes since an internal reference point is used for those probes.
Reference Manual
Service and troubleshooting
00809-0100-4530
April 2019
Reference Manual
201