Precision Measurement Engineering, Inc.
Precision Measurement Engineering, Inc.
| PERSONAL DANGER FLOOD SHIPPING SENSOR GUARD CLOTHING |
ROCKS RELEASE CABLE DAMAGED SENSORS TESTS BEFORE A FIELD TRIP USEFUL ITEMS (NOT SUPPLIED BY PME) |
If the SCAMP becomes substantially filled with water
at depth, then it can return to the surface containing high pressure. If you have reason
to believe that the SCAMP has flooded, such as failure to communicate or bubbling at any
seal, then treat the SCAMP with extreme caution. Internal pressure may be released by
carefully loosening the pressure test screw and allowing several minutes to pass. This can
be done from the side using a screwdriver. Do not allow any part of
your body to come into alignment with either endcap since these may unexpectedly be
explosively expelled by internal pressure.
FLOOD
Should a SCAMP seal fail and allow the SCAMP to become
flooded with water, open it, immediately drain the water, and remove all batteries. Remove the
electronics covers and completely flush the covers and all circuits with large
quantities of distilled water. Leave the SCAMP open so that it will dry. Allow it to dry
completely, then close it and return it to PME for inspection.
SHIPPING
Save the cardboard shipping box (12" x 12" x 36") that contains the SCAMP. This may be re-used to ship SCAMP from point to point or to return the SCAMP to PME. Do not ship SCAMP in any other container. If the cardboard box becomes unusable, then obtain another either from PME or some other convenient source.
When re-packing the SCAMP in the shipping box
be sure to use all four pieces of foam. The two pieces with the hole in the middle of
the SCAMP and the other two at either end of the box. This will help keep the SCAMP
centered in the box. Fill box with popcorn.
The grey flip pack will contain all the SCAMP elements except the SCAMP itself.
It takes a little arranging, but everything will fit. The tent stand PVC pipes lay
on the bottom at one end. Place the cable assembly upright at the other end. Next, the
drag plate unit fits well between the PVC pipes and the cable assembly. The guard can fit
in this area too, but might need to be nested somewhat with the PVC pipes inserted into
its interior. Make sure that it is positioned so that the supports do not become bent. The
tent folds flat and can be placed on top.
When storing or shipping be sure that the sensor guard is securely packaged so that it cannot be bent. No disassembly is required.
After screwing the sensor guard onto the SCAMP, use a small cable tie or bit of dental floss to tie one of the guard's legs to one of the sensor seal nuts bases. This will prevent the unscrewing of the guard during a SCAMP deployment. Should the guard come unscrewed the retrieval cable can slip loose and the SCAMP will be lost. The sensor guards screw on tightly, but this extra precaution is low-cost insurance.You will find it difficult at best to see the laptop
display in direct sunlight. Experience has shown that much of the glare on the laptop
screen can come from light reflected from the operator's clothing. Wear something dark.
Tying the release cable to the rock is often a
problem. Some suggestions are: cable tie the rock first, then tie to the cable tie, use a
plastic zip lock bag to contain the rock, or use several rubber bands. Additional
suggestions will be greatly appreciated.
Make these in advance of a field trip. They are only used for upwards profiling. There is a tool provided for creating the proper size loops to fit on the release screw.
Locate enough expendable weights (rocks) for the profiles you intend to make. Make wire loops from the wire provided by threading the wire through the crimp to make a loop, then adjusting the loop size using the tool provided. Crimp the collar in place with pliers. Connect the other ends of the wires to the expendable weights so that the weights will hang below the SCAMP by at least 12 inches (30cm).
When you run out of release cable and crimps you can re-order these
from PME, purchase similar materials at your local fishing shop, or make release cables
from 50# test fishing line. (For fishing line tie a slip-knot so that it tightens due to
the weight of the rock. These aren't optimal since they do tend to slip off if the
rock tension is lost.)
PME part numbers for additional crimps and release cable are:
4580 - crimp, each (please order in groups of 100 crimps)
4581 - release cable, roll of 100 feet
Damaged conductivity sensors should be replaced, or at least have dummy sensor plugs installed in their place. Damage to Fast Conductivity sensors can admit water into the SCAMP by allowing it to travel down the Fast C glass tubes and along the connecting wires. The conductivity circuits operate the sensor using an AC signal. In some cases, if the sensor is damaged or not installed, the circuit can enter an oscillating mode. This doesn't damage the circuit, but can induce a large amount of electrical noise in the other sensor channels in the SCAMP. Dummy sensors must be electrically connected in place of damaged conductivity sensors.
Damaged temperature sensors need not be replaced since there are no likely leak paths. Temperature circuits will not oscillate, but if the sensor is seriously damaged they can put out large voltages that will affect the other channels. Damaged temperature sensors must be at least electrically disconnected and dummy sensors connected in their place.
Damaged oxygen sensors should be replaced because of leak possibilities along the wires within the sensor. There is no dummy sensor required. Simply disconnect the oxygen sensor.
See Replacing a Sensor section for more detailed information concerning sensor replacement and Installing a Dummy Sensor for dummy sensor information..
Many features of the SCAMP should be tested prior to using it for data collection. These tests should be accomplished several weeks prior to the expected use to allow time for repairs and re-calibrations should these become necessary. Some of the tests should also be done on a daily basis or at other intervals. Many of these assume that the SCAMP is connected to the host computer and that the SCAMP Control Dialog is running.
Analog test
. This test should be done in advance of a field trip. Click the Display button in the Analog Test section of the Test Tab. See the Analog Test section for the proper test result.Battery test
. This test should be done in advance of a field trip and frequently during use. Simply review the System Tab battery indications.Temperature sensor test
. This test should be done in advance of a field trip and on a daily basis. If not already done, fill the sensor cover with tap water at ambient temperature or at the highest limit of SCAMP temperature channel calibration. Rock the SCAMP back and forth to gently mix the water in the sensor cover. Make sure that it is completely mixed. Stop rocking the SCAMP and wait a moment. Record a brief profile with SCAMP. Pour out the water in the sensor cover and replace it with ice water, or water cooled to the lowest limit of SCAMP temperature channel calibration. Be sure that no ice enters the cover as it can damage the fast sensors. Record another brief profile. Upload both profiles and review these using the Matlab software. Check that all temperature sensors agree within 0.050 deg C. If larger differences are observed at either temperature, then contact PME.Conductivity sensor test
. This test should be done in advance of a field trip and on a daily basis. Fill the sensor cover with salty water of conductivity near the upper limit of SCAMP conductivity channel calibration. Rock the SCAMP back and forth to gently mix the water in the sensor cover. Make sure that it is completely mixed. Stop rocking the SCAMP and wait a moment. Record a brief profile with SCAMP. Upload this and review using the Matlab software. The difference between Accurate and Fast Conductivity should be less than a few percent. If it is not, then carefully inspect the Fast Conductivity with a magnifier for fouling of the electrodes or cracks in the glass near the base or near the electrodes. Cracked sensors must be replaced. Fouled sensors can be cleaned (process being developed now). Re-calibrate the Fast Conductivity sensor using the Accurate Conductivity as a reference.Fluorometer test (for SCAMPs with fluorometers installed)
. Record a brief profile with SCAMP while inserting and removing a blade of grass into the fluorometer measurement tube. Upload the profile and review using the Matlab software. The fluorometer should show a low voltage in the 0.1 to 0.5 Volt range with no grass in the tube and show a high voltage with grass inserted. The actual amplitudes will depend upon the sensitivity adjustment of the fluorometer.Seal leakage test
. This test should be done in advance of a field trip and after changing SCAMP batteries. For more information see the Testing for Leaks section.If the above tests are all completed successfully, then nearly all
of SCAMP's features will be verified.
| scissors | for cutting lead ballast weights |
| duct tape | for connecting the weights to the SCAMP |
| screwdrivers | small standard and phillips |
| heavy dark cloth | used to view the laptop computer; cover the computer tent and yourself to block the sun |
| pliers | for squeezing the weight release line collars and operating the sensor seal nuts |
| voltmeter | for checking battery voltages |
| cable ties | for securing the guard against unscrewing |
| laptop computer power | use a large capacity battery with an AC invertor so that the laptop can be powered by using its AC plug-in power supply |
| spare batteries | for use in the SCAMP and especially the laptop |
| laptop serial port | An extender cable is required for the laptop serial port since the SCAMP RS485-RS232 adaptor is too long to plug directly into the port. Allows the computer to easily fit into the tent. |
| squirt bottle | fill with DI water to clean the sensor shafts and pressure transducer |
| float | If the SCAMP becomes tangled on the bottom, then it may be necessary to leave it to obtain diving gear. Attach the float to the retrieval line to act as a marker. |
| o-ring grease | for lubricating the various o-rings |
| spare sensors | for replacing damaged sensors |
| panavise | use two for holding the SCAMP to replace sensors or service the instrument |