Testing In Place Inclinometers installed in the borehole
Conductor information and identifying uni-axial or bi-axial IPI
Red - Power + 12-16V DC
Black - Ground –
White - Signal High A-axis (uni-axial & bi-axial)
Green - Signal Low A-axis (uni-axial & bi-axial)
Blue - Signal High B-axis (bi-axial IPI only)
Yellow - Signal Low B-axis (bi-axial IPI only)
Shield - Bare Wire
Test 1 – IPI functionality
When powered a fully functional IPI will output a signal of ±2.5v
(±2500mV) depending on the sensors inclination. Using a power supply and
voltmeter, a basic function test can be performed on the sensor.
The sensors require a power supply of 12-16v DC. Connect the sensors
black wire to the power supplies negative output and the sensors red
wire to the power supplies positive output. It is important to make sure
you do not apply power to any of the sensors signal wires, if you do
you are likely to damage the IPIs internal sensor.
Now the sensor
is powered you should receive a voltage reading from the sensors signal
wires. Using the voltmeter record the voltage reading from the signal
wires. Set the voltmeter to measure DC voltage and connect the red probe
from the multimeter to the signal high wire and the black probe to the
signal low wire. You should receive a stable reading in the range of –
2500mV to +2500mV. If the sensor displays anything other than a stable
output then please check the following
a) The voltage input is 12-16v DC.
b) You a measuring across a pair of signal wires, A-axis or B-axis
c) Perform test 2 “Continuity check” to help determine if there is any damage to the sensors cable.
d) Perform test 3 “In line current draw test” to check the functionality of the internal sensor.
Test 2 – Continuity checking
We perform the continuity test to check if the cable has been damaged and is shorting on the outer shield.
To perform the continuity test, please set your voltmeter to the
continuity testing mode. Depending on the voltmeter this can be
identified by a symbol that indicates an audio alert ?, or sound wave .
To make sure you are in the correct mode touch the multimeter probes
together and you should get an audio alert.
Once in continuity
mode proceed to test each of the four cores of the cable. Connect one of
the probes from the multimeter to the cables shield and the other to
one of the cables cores. Once connected listen for the audio indicator
and view the multimeter’s LCD screen.
If there is a short or
continuity is present, the multimeter will give an audio warning and the
screen will display the resistance on the circuit.
If there is no
short or no continuity, the multimeter will not give an audio warning
and the screen will display “1” or “OL” (open loop) this display is
dependant on the multimeter please consult the multimeter’s manual to
verify.
Please perform this test for each individual core and
record the results. When testing IPI’s we expect to get no short / no
continuity. If continuity is present this indicates cable damage and the
cable will need to be inspected and repaired.
Test 3 – In Line current draw test
If we suspect that the internal sensor is not functioning we can
perform an in-line current draw test to see if the senor is active. To
do this we will need a 12-16v DC power supply and a multimeter.
Set the multimeter to measure current. This is normally indicated by a “~” symbol over the top of “mA”
Connect the sensors black wire to the power supplies negative output.
Connect the multimeter’s red probe to the power supplies positive output
and the black probe to the sensors red wire. If the sensor is
functional, there should be a current draw of about 9mA (uni-axial) and
17mA (bi-axial) if the sensor is not functional then there will be 0mA
draw, a damaged sensor would draw more than 20mA.