Dwyer ULTM - Manual (Page 16)

B) Distance to Empty Level
Distance to empty level is defined as the distance from the face of the sensor to the
bottom-most surface of the target to be measured. For typical installation in tanks,
the bottom-most surface is usually the floor of the tank.
ULTM supports a maximum range of 26´ (8 m) and the default value for distance to
empty level is therefore 26´ (8 m). The user is cautioned however that the maximum
practical range depends on target characteristics. Range of 26´ (8 m) may be
achieved with quiet liquid surface targets. As a rule of thumb, use no more than 20´
(6 m) for solids, turbulent liquids, when the air medium is not clear, or when
interferences exist. You may verify proper operation by checking whether the
equipment frequently enters a state of “echo search” at your maximum distance.
When ULTM enters the empty level, it will present an empty status on the display.
ULTM will then exit this state when level rises at least 0.8˝ (2 cm) above the empty
level.
C) Distance to Full Level
Distance to full level is defined as the distance from the face of the sensor to the
top-most surface of the target to be measured. The default value for distance to full
level is 5.9˝ (15 cm). This is also “dead zone” of ULTM and cannot be reduced
under any circumstances.
The user is cautioned to prevent targets from crossing this limit, as this may result
in unpredictable measurements. You can overcome this limitation by proper
installation. For example, if the target can approach the tank roof, install ULTM on
top of an extension pipe which is at least 5.9˝ (15 cm) long.
When ULTM enters the full level, it will present a full status on the display. ULTM
will exit this state when level decreases by at least 0.8˝ (2 cm) below the full level.
D) Far Blocking Distance (FBD)
ULTM normally measures distance to targets which are closer than the “Empty
Level”.
In some circumstances, ULTM might detect an echo which is further out than the
“Empty level”. This echo may be the result of the actual target below the empty
level, or a strong interference below the empty level. In such cases, ULTM would
report “Empty” and would transmit an SMS to report the event. If you expect
echoes further out than the empty level, and you prefer to avoid these event
reports, you can define a Far Blocking Distance (FBD). Once defined, ULTM will
completely disregard any echoes beyond the FBD. If no other echoes closer than
FBD are detected, the ULTM will report loss of echo.
The default for “Far Blocking Distance” is identical to the maximum range of ULTM.
E) Near Blocking Distance (NBD)
If distance between the sensor face and the topmost level of the target is larger
than the specified “dead zone” by at least 2.7˝ (5 cm), you should consider defining
a Near Blocking Distance (NBD). The NBD should be defined as 0.8 to 1.2˝ (2 to 3
cm) shorter than the distance to the topmost level. This will ensure that the ULTM
will not measure obstructions slightly above the topmost level and mistakenly report
them as full level.
Similarly, when an extension pipe is used and the length of the extension pipe is
larger than the “dead zone”, you should define NBD which is larger by 0.8 to 1.2 in
(2 to 3 cm) than the length of the extension pipe. This will ensure that you will not
pick up echoes arising from the bottom end of the pipe and report them as full level.
If no other echoes further than the NBD are detected, the ULTM will report loss of
echo. The default for “near blocking distance” is identical to the “dead zone”.
Application Type
Application type allows some tuning of the internal GSM algorithm to be tuned to
the application. The application may be selected as low power or high power.
Always use low power for stable measurements unless your target appreciably
attenuates the echo such as: powder solids, liquid with foam, or long extension
pipes.
Cellular Communication
ULTM is equipped with an integrated cellular modem allowing periodic reports of
measured data and immediate alerts. Alerts include empty and full states and
excessive level change rates. Excessive level change rates may indicate theft or
tank refilling or an approaching flood. The user can configure the destination phone
number, periodic reporting interval, normal level change rates and more. The user
can activate or deactivate specific alerts.
The modem is of the quad-band GSM type and cannot be used with other cellular
standards. An antenna is connected internally within the ULTM. A SIM card must be
inserted into ULTM. The SIM card must adhere to the instructions provided in the
installation chapter. Carefully read and comply with these instructions.
Contact Alert
Contact alert identifies a change of an external on/off state and transmits an SMS
alert to report the event. The contact alert does not affect other SMS message
types which are initiated by ULTM. The on/off states identified by ULTM are
OPEN/SHORT between pins 5 and pin 4 on ULTM connection board.
A change in state is reported only if the new state persists for more than 10
seconds. No SMS is transmitted if the state toggles for less than 10 seconds. A
change to OPEN state is reported by a standard SMS message with status field “9”
(last field in the SMS message). A change to SHORT state is reported by a
standard SMS message with status field “8”.
At ULTM turn-on, a special message is transmitted to report the initial contact state
with “9” designating an OPEN state and “8” designating a SHORT state.
Default Values
ULTM is preset by the manufacturer to a set of default values. The user may revert
at any time to these default values by performing the reset-to-default operations as
described in the configuration chapters under “Device States”.
Changes to the values made by the user will remain intact (survive equipment
on/off) only after the user returns to the measurement screen.
The table below defines the default values. A default value may automatically
change in response to a change in some other value. For example, default value of
full is 5.9˝ (0.15 m). This value will automatically be changed to 1.6´ (0.5 m) if NBD
is set to 1.6´ (0.5 m).
Destination Phone Number
The SMS destination phone number (can be up to 14 digits) must be defined in full.
Any hyphen signs (“-“) are ignored. Examples:
• A 10 digit phone number 0541234567 may be entered as any of the following:
• The number *2345 may be entered as any of the following:
Distance Units and Value to Display
Either meter or feet may be selected for the distance unit. This selection defines the
complete unit system being used by ULTM. Selecting meter as your distance unit
implies the Metric unit system.
Page 15
Parameter
Distance Unit
Application
Empty Level
Full Level
Value to Display
FBD
NBD
Filling Rate
Temperature Units
Temperature Sensor
GSM Report Interval
Full / Empty Activation
Theft Activation
Refill Activation Default Value
Meter
Low power
8.000 meter
0.150 meter
Distance
8.000 meter
0.150 meter
5 m/min
Celsius
Internal
1800 seconds
1
0
0
1
-
0
-
2
-
5
-
3
0
4
-
4
5
1
-
5
4
2
0 6
-
3
5
7
1
4
4 8
2
5
1 9
3
6
2 10
4
7
3
11
5
-
4
12
6
-
5
13
7
-
6
14
-
-
7
1
*
-
-
2
2
-
-
3
3
-
-
4
4
-
-
5
5
*
-
6
-
-
-
7
-
2
*
8
-
-
2
9
-
3
3
10
-
-
4
11
-
4
5
12
-
-
-
13
-
5
-
14
-
-
-
Depending on the unit’s location and carrier, a country code and
operator prefix may be necessary. Please add these as
appropriate. It is your responsibility to insert the correct phone number as phone
number schemes vary worldwide.
CAUTION