Each Hydrolab DS5 sonde contains seven sensors, measuring:

  • dissolved oxygen
  • conductivity
  • pH
  • turbidity
  • chlorophyll a
  • depth
  • temperature

We typically loan out the equipment for 10 days, which includes shipping overnight there and back. 

The equipment is only available from April–October. The operating temperature for the Hydrolab goes down to 23° F. However, EPA reserves the right to decline sending during very cold weather. The biggest concern regarding borrowing in the winter is shipping when air temperatures are below freezing. Another concern is the transition time from being in a warm spot (e.g., school) to the monitoring site, as well as at the site, how much time the equipment spends out of the water.

The C batteries go in at the top of the Hydrolab. The silver knob at the top screws into a plastic piece, which is kidney shaped. It might be tricky getting the plastic cap off since it has a waterproof seal. Grip the cap, using the indentations on each side, and rock the cap from side to side to loosen the seal. The Hydrolab takes eight C batteries (provided).

The recharge time depends on the percent left (IB%) in the battery. Charging is complete in 3.5 hours. It is recommended that you recharge when the Surveyor internal battery voltage (IBV) reaches 6.5 volts. 

The Surveyor must be on to charge. Pressing the Suspend key will pause the recharge process. Press Resume to restart the recharge process. 

It is recommended that you do not disconnect the Surveyor from charging until prompted. Early disconnect can reduce operating time. The Surveyor will display “Charging Complete! Disconnect Charger for Normal Operation. Press any key…” when the charge event is complete. 

Check the IBV reading on the display. Charge the Surveyor battery if its at or below 6.5 volts. Make sure that you turn on the Surveyor when you start charging. It won’t charge if it hasn’t been turned on. Pressing the Suspend key will pause the recharge process. Press Resume to restart the recharge process.

A screensaver option has been enable to conserve power. This feature puts the Surveyor to sleep if no key is pressed within a couple minutes. If the screen shuts down, press any key once and the screen will reappear with the last screen displayed.  

If Surveyor power continues to be an issue, please contact the IISG Great Lakes educator

If an incomplete connection is made between the fully-charged Surveyor and the Hydrolab this message will display. Check all connections. Make sure that the plug is flush and the plug cover is screwed down over it. Next, check that the serial port is connected securely to the Surveyor and the screws are tightly screwed down. If that doesn’t help, try changing out C batteries in the Hydrolab.

Use this checklist to make sure all items are returned to the Pelican case.  

  • Remove the C batteries from the Hydrolab and store them in the case. 
  • Please clean off the Hydrolab, rinse off the cable and deployment line and make sure all equipment is dry before packing things up in the case. 
  • Carefully wind up the cables and dry the deployment line. 
  • Ensure that the calibration cup is on the Hydrolab with 1/2 inch of water to prevent the probes from drying out. (Do not put water in the little cap that protects the pH probe.)
  • Sign the green guest book. We encourage your students to comment! 

A pre-paid UPS mailing label is provided by the EPA mailroom for each loan. Remove the old shipping label and attach the new label to the Pelican case. You can  schedule a UPS pick-up or take the labeled Pelican case to your nearest UPS drop-off location

Student standing at the edge of a dock and lowering the Hydrolab data sonde into the water below.
Photo Credit: Melissa Kowalski