Siemens LU01 instruction manual P831 TVT Shaper, P832 TVT Shaper Adjust, To change a breakpoint

Parameters

Select the TVT type which gives the highest confidence (P805) under all level conditions. Use this parameter with caution, and do not use TVT Slopes with the bF or bLF Algorithm (P820).

P831 TVT Shaper

Turns the TVT Shaper ON or OFF.

Values	0	*	Off
	1		On
Related	•	P832 TVT Shaper Adjust

Turn the TVT Shaper ON before using P832 and afterwards. Turn the TVT Shaper ON and OFF while monitoring the effect to pick up the true echo.

P832 TVT Shaper Adjust

Allows manual adjustment of the TVT curve.

Primary Index	Breakpoint
Values	Range: -50 to 50
	Preset: 0
Related	•	P810 Scope Displays
	•	P831 TVT Shaper

Use this feature to bias the shape of the TVT curve to avoid selecting false echoes from fixed objects.

Adjust this parameter while viewing the echo profile with Dolphin Plus. Refer to the Dolphin Plus online help for details. If Dolphin Plus is not available, then an oscilloscope can be used. When using an oscilloscope, the Echo Lock Window display becomes the TVT Curve Pointer. See P810 Scope Displays on page 71 for more information.

The TVT curve is divided into 40 breakpoints, accessible by enabling the point number as the breakpoint index field. Each breakpoint is normalized to a value of 0, as displayed in the parameter value field. By changing the breakpoint value, up or down, the intensity of the bias applied to that breakpoint of the curve is respectively changed. By changing the value of adjacent breakpoints, the effective bias to the shaper can be broadened to suit the desired correction. In the case of multiple false echoes, shaping can be applied along different points of the curve. Shaping should be applied sparingly in order to avoid missing the true echo.

To change a breakpoint

1.Confirm that P831, TVT shaper, is on.

2.Go to P832.

3.Press MODE and then press DISPLAY to access the Breakpoints.

4.Press MODE to select the Auxiliary function.

5.	Press P		to scroll the breakpoint index through points 1 to 40, and move the
		P
	curve pointer right or left respectively.
Page 76			SITRANS LU01 – INSTRUCTION MANUAL	7ML19985BE02