PME Products

Frequently Asked Questions

Please e-mail SCAMP questions to mhead@pme.com. More SCAMP Questions

These questions have been sent to us from customers who are currently using SCAMP in the field.

Shipping SCAMP Back to PME
PME ships SCAMP in a double-box method. The smaller box size is 12 x 12 x 36 and is the box that the SCAMP is packaged in. This box is then placed within another box with dimensions of 14 x 14 x 36.

SCAMP Packaging Instructions: We suggest using four foam squares in order to package SCAMP. The foam squares are 1' x 1' x 2" thick and should fit perfectly inside the box. (photos below). PME cuts a circle (SCAMP diameter) in the middle of two foams. This will help hold the SCAMP in the middle of the box. Two foams are left uncut. These are placed at the very bottom of the box and at the very top. The two foam with the central hole are placed at each 1/3 distance within the box.

Place the uncut foam at the bottom of the box, then add some popcorn to about a third of the way. Place a cut foam on top and position SCAMP (sensors down) through the hole. Add more popcorn to fill the box to 2/3 point and then place another cut foam piece around SCAMP. Fill the remainder of the box with popcorn. The last piece of uncut foam should be placed on top and then the box closed and sealed with tape. Box Dimensions

SCAMP is originally shipped using this packing method. Please retain the original boxes for return shipping.

If you are unable to find the correct materials PME can ship them to you at a nominal cost. Please contact PME.

DO NOT ship SCAMP using any other packing method such as foam lined plastic cases. SCAMPs received by PME that are packed in other packing will be returned in the box described above. If the other packing method is valuable (such as a plastic case) it will be shipped back separately.

Suggestion for Shipping SCAMP
A recent customer of ours shipped their SCAMP back to us in a gray plastic Flip Pak (dimensions 27.5 x 20.5 x 15.5) and decided to create handles made out of rope and tubing. Two photos are below.

FAQs (USB SCAMP)

Q. How can I calibrate my Accurate CT Sensor?

View the Emergency Calibration manual

Q. Should I leave SCAMP connected to USB when it is not uploading data or having its parameters changed?
No. SCAMP will not return to its sleep state if it is connected to the USB port of the host computer.

Q. What are SCAMP's internal power modes?
SCAMP has three principle power modes: Awake and idle - SCAMP enters this mode when connected to the USB, Awake and acquiring data - SCAMP enters this mode after activation with the start magnet, Sleep - SCAMP enters this mode when not connected to the USB and when data collection is completed. In the Awake modes, SCAMP consumes substantial battery power. Batteries will last only a few hours in this mode. In Sleep mode SCAMP consumes very little battery power. Batteries will last weeks to months in this mode.

Q. My SCAMP doesn't respond to warm temperatures. I think these temperatures are above the calibrated range.
The best way to correct this problem is to return SCAMP to PME for calibration. The next best way is to simply tell SCAMP that your water is warmer. Connect SCAMP to you computer. Run the SCAMP Control Dialog. Select the Channels tab. Select Fast T0 as the channel. Look at boxes on right. There is a Span Max and Span Min. What's the max temperature of your water? Add 1 degree, round up, put the result in the appropriate span box. Select Fast T1, do the same. If there is an Accurate T on this SCAMP then repeat for this channel. Select the OK button and you should see the SCAMP Control Dialog disappear from your screen. When you select OK your selections are sent to the SCAMP and implemented thereafter. After this procedure your T calibrations will be slightly inaccurate, maybe you'll see errors of 0.1 deg C.

FAQ's (General Questions)

Q. Can SCAMP be used in a moored situation?
SCAMP's main objective is to determine the turbulent rate of energy dissipation. This is done by matching observed temperature gradient spectra to theoretical Batchelor spectra for a passively transported scalar. Where matches can be found the dissipation is computed from kB.

This method works well where the water is non-thermally uniform, but depends upon knowledge of the spatial distribution of temperature since the Batchelor spectral form is a function of wave number. Unfortunately, SCAMP can only measure temperature at fixed time intervals. The time-spaced interval is transformed to the distance-spaced interval required for Batchelor fitting by using SCAMP's velocity through the water. Since SCAMP is a vertically profiling device, this velocity can be determined from the rate of change of hydrostatic pressure.

In a moored situation some other method of determining velocity must be provided. Yes, you can moor SCAMP but it will not, of its own measurements, be able to determine dissipation. You must provide some other way to measure water velocity past SCAMP's temperature sensor.

Assuming that you provide some independent velocity measurement there are yet more subtle problems. SCAMP's temperature sensor cannot respond to temperature variations that occur too rapidly. This limits SCAMP's use to roughly 10 cm/sec. This velocity is established when profiling by adjusting SCAMP's buoyancy. In a moored situation you'll have to take what you get. If you expect 5 - 12 cm/sec SCAMP may work.

Q. I would like to use SCAMP deeper than 100m. Is this possible?
SCAMP is designed for 100 meters maximum depth. We have no experience with its use at deeper points. SCAMP's pressure transducer is a 10 Bar device (145 PSI). At 200 meters it will be 2X range and may be permanently damaged. This can be swapped for a higher pressure sensor, but PME can only calibrate to 70 meters so the higher range would have to be extrapolated unless the customer does the depth cal.

Also , I can't promise that the system will be free of leaks or will resist implosion. My gut feeling (about 80% confidence) is that it will survive. I wouldn't use a Fast C sensor, but the other sensors (Acc CT and Fast T) should be OK at 200 meters. F-meter shouldn't have any problems either.

So I think SCAMP will work but you should plan to install a pressure sensor with the appropriate range.

I strongly suggest that if you intend to use SCAMP deeper than 100m, make the necessary modifications, and then thoroughly test it at 200 meters. Better to have it implode in a test chamber then at the end of a retrieval line.>

SCAMPs built with serial numbers ranging from SN0001 to SN0030 hold data internally, but have space for only 100 meters of 8 channel data. We are re-designing the SCAMP to contain up to 8000 meters of 8 channel data in multiple files. These SCAMPs can be retro-fitted with this new feature.

Q. How should I store sensors for long periods of time (weeks)?
Take the batteries out of SCAMP, flush the sensor cover with distilled water several times and store SCAMP with the sensor cover plug removed so that things dry inside. When getting going again put batteries back in, put tap water (slightly conductive, maybe 1 mS/cm) into sensor cover. Let things soak for a few hours or a day.