Endress+Hauser Proline Prosonic Flow 93T Portable Operating Instructions Manual page 108

Description of Device Functions
108
BASIC FUNCTIONS PROCESS PARAMETER LIQUID DATA
TEMPERATURE
(6541)
SOUND VELOCITY LIQUID
(6542)
Functional description
Use this function to enter the process temperature of the liquid. Via the sound velocity,
the value influences the determination of the sensor distance. Enter the process
temperature at normal operating conditions to achieve an optimum configuration of
the measuring system.
User input
Fixed-point number –273.15 to 726.85 °C (0 to 1000 K)
Factory setting
20 °C
This function displays the sound velocity of the liquid. This is determined by the values
entered in the LIQUID (6540) and TEMPERATURE (6541) functions. If you edit the
predetermined value the function LIQUID (6540) will be set to the option OTHERS.
The sound velocity of the liquid has to be entered if the liquid is not available for
selection in the function LIQUID (6540) and the OTHERS option was selected.
Measuring the sound velocity of the liquid
If the sound velocity of the liquid is unknown, it can be measured. To do so, select the
option SOUND VELOCITY LIQUID in the function MEASUREMENT (6880,
 ä 111). The sound velocity in the liquid is measured by calling up the function
SOUND VELOCITY LIQUID (6542). The result of the measurement appears on the
local display. If you confirm the function with the F key, the SAVE prompt appears. To
accept the measured sound velocity, select the option YES by means of the O or S
key.
!
Note!
To measure the sound velocity, you require the ultrasonic sensors "DDU18" which you
can order as an accessory from Endress+Hauser.
Transmitter search range:
The measuring device searches for the measuring signal within a defined sound
velocity range. You specify the search range in the SOUND VELOCITY NEGATIVE
(6545) and SOUND VELOCITY POSITIVE (6546) functions. An error message is
displayed if the sound velocity of the liquid exceeds the search range.
!
Note!
We recommend you select a smaller search range in the event of unfavorable signal
conditions (signal strength < 50%).
0-1000
2
1. Sound velocity of the liquid
2. Lower search range: is specified in the
SOUND VELOCITY NEGATIVE (6545) function
3. Upper search range: is specified in the SOUND VELOCITY POSITIVE (6546)
function
User input
Fixed-point number 400 to 3000 m/s
Factory setting
1485 m/s
Proline Prosonic Flow 93T Portable
0-1000
v [m/s]
3
1
Endress+Hauser
A0001246