pH Loggers

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The protocol for calibrating/initializing, deploying, and offloading Data from the HOBO pH loggers.

The pH loggers require the iPad with the special HOBO software

Initializing Loggers

Calibrating the Logger

To initialize the logger:

  1. First, make sure you have the IPad the is used for the pH loggers

  2. If the logger isn’t on, turn the logger on

  3. Under ‘IN RANGE’ the logger should appear. Select the correct logger

  4. If the logger has an expired calibration, you will be promoted to calibrate the logger. If it isn’t expired, you should still calibrate before deploying by selecting ‘pH Calibration’

  5. This will open a window with a very easy-to-follow guide on how to calibrate the logger. We typically do a three-point calibration, so choose ‘Three-Point’ Follow the important tips at the bottom of the page. Namely, make sure the copper tip has been removed before calibrating and make sure the temperature logger is fully submerged when calibrating

Tip: Have the logger in the 7 pH buffer before clicking ‘Start Calibration’ and before clikcing ‘Next Buffer’ for the 4 and 10 pH buffers

If you put it in the wrong buffer or click ‘Next Buffer’ before putting the logger in, you should be able to place the logger in the buffer and it will properly stabilize

Configuring and Launching Logger

After the logger has been calibrated you can configure it and launch it. To do so:

  1. Choose ‘Configure’ under the ‘Actions’ list

  2. Some things I would change: Name (to something meaningful like 20180615_Barnstable_pH), Logging Interval (typically 30 min), Start Logging (to the date and time it will be deployed, or ‘Now’ if relaunching), Stop Logging (make sure it’s on ‘When memory fills’), and make sure bluetooth is always on.

  3. Click ‘Start’ and the logger should launch at the date and time you set.

Deploying loggers

Materials you’ll need before deploying

  • Cinderblock

  • Metal tubing straps to attach PVC fixed loggers to

  • Zipties

  • PVC pipe large and long enough to fit logger, “swiss-cheesed’ with holes There must be enough holes for regular flow of water through the PVC pipe. The PVC pipe prevents large rocks and debris from damaging loggers

  • Rope and buoy

  • Glass bottles and 50 mL Falcon tubes. See this page for water sampling protocol

Before leaving for the field

  1. Attach metal straps to cinder block

  2. Attach PVC pipe to the metal rings that are fastened to the cinderblock

  3. Label cinderblock, PVC pipe, buoy, and loggers with contact information (Katie’s)

  4. Make sure you’ve contacted local shellfish constable to make sure they can keep an eye on the logger

Deploying

Loggers should be deployed at low tide, so that we know they’ll be constantly exposed to water while logging

  1. Before deploying, attach logger(s) to PVC using many zipties IMPORTANT: MAKE SURE THE COPPER GUARD HAS BEEN PLACED ON SENSOR BEFORE DEPLOYING

  2. Wade to waist-deep water at site of deployment

  3. Deploy logger

  4. Record time of deployment. If loggers start logging before they are deployed they give strange readings. It is good to know when the logger was actually deployed, so we know when logging was actually initiated

  5. Record location using GPS

  6. Take water samples

Last Steps

  1. Add the geographic location, deployment time, and additional notes about site to the log file (should be a google doc- ask Katie)

  2. Make sure field sample in glass bottle has been poisoned with Mecuric Chloride (Ries Lab) and place in freezer

Offloading Data

Data from loggers should be off-loaded about every two weeks

Materials you’ll need before going into the field for off-loading data

  • Glass bottle and 50mL Falcon tube fore water samples

  • IPad with HOBO software

  • Kimwipes

  • Wire cutters (to clip zipties)

  • Zipties- to reattached logger

Transferring Data to the iPad

  1. Retrieve logger and record the time you collected logger

pH protocols is not finished