SPM BC100 - Transducer Line Test; Storing Measurement Results

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Transducer Line Test
When measuring shock pulses with external transducers, a
transducer line test (TLT) will automatically be made to check
the quality of the signal transmission between transducer and
instrument (the TLT value for the latest reading is always saved
and is shown in the TLT window). Part of your signal will be
lost in a poor transducer line, so your measuring results will
be lower than they should be. If an SPM measurement is made
with a poor transducer line, the instrument will display a TLT
warning sign.
To perform a transducer line test (TLT) manually, connect the
external transducer to the instrument. From the Main display,
press the UP arrow key to enter the Bearing folder, then use
LEFT/RIGHT arrow keys to highlight the TLT icon. Press the
UP arrow key to enter the TLT menu. Press the measuring key
briefly. The blue measuring LED lights up and the reading is
shown in the display.
The TLT test window also displays transducer type: IPR (internal
probe), EPR (external probe), TRA (40000 type) or TMU (42000
type). TRA is also displayed in case of a cable breakdown. The
TLT value then depends on the distance to the breakage point
(1-2 dB/meter). In case of a shortcircuit, TMU and the value 0
(normally) is displayed.
At TLT values from 15 upward, there is normally no signal loss
due to poor transmission between transducer and instrument.
If the value is below 15, or if it is deteriorating from a previ-
ously higher value, you need to check cables, connectors and
transducers for poor connections and moisture.
The TLT test can be temporarily turned off to force evaluated
measurement results on transducers with TLT below 15, e.g.
when measuring via coupling transformers. In the TLT menu,
press the RIGHT arrow key to turn the test off. The TLT test is au-The TLT test is au-
tomatically turned back on by entering the TLT menu again and
when the instrument is automatically or manually turned off.
Storing measurement results
This function is useful for easy comparison of measurement
results for a particular measuring point. It can also be used to
store measurement results temporarily until they can be re-
corded on paper for trending and follow-up. On the last page
iof the User Guide is a follow-up form which can be copied and
used for this purpose.
The Bearing Checker can store up to ten SPM measurement
results.
In the Bearing display, use LEFT/RIGHT arrow keys to highlight
the Memory icon, then press the UP arrow key to enter Memory
mode. Select memory place (1-10) by using the UP/DOWN ar-
row keys. Press the RIGHT arrow key to store the reading. This
action will overwrite any previously stored value in the memory
place selected.
To return to the Bearing display, press the LEFT arrow key.
Latest reading
Stored reading
Current memory place
dBi
Transducer Line Test
Bearing measurement
Measure
TLT
Save
Select place
Memory
Bearing measurement
TLT off