Zen and the Art of Waterfowl Maintenance

Figure 1. My Little Buddy Nick Page (MLBNP) was able to solve the DB-9 mind puzzle in the Feature Image.  I’m super proud of the little guy.  He worked on it for days.

Our goal is to have the QQ self maintaining, like the fellow in the feature image, or not require any maintenance or troubleshooting. Until this vision is realized, we appreciate you patience and diligence.
We’ve been meaning to publish this for post for some time, and with Christmas around the corner, and nothing else to give you, it seemed opportune to publish now.

QiQuac Maintenance

Opening the QQ and T-HRECS and Changing the Desiccant

  1. To open the QiQuac, remove the antenna extension, nut, washer, and remove the screws fastening the lid to the box. When removing the lid, angle it towards the antenna hole and pull up at that angle. This will avoid dismounting the radio module. The XBee radio should have a piece of tape over top of it holding it fast to it’s slots.
  2. To open a T-HRECS unit, remove the screws fastening the lid and then remove the lid.

    Figure 2. To open the QiQuac, remove 4 top screws, and the nut and washers on the antenna base. Lift the right hand side of the face plate and slide away from the antenna hole. The Antenna base is attached to the face place.

Look for signs of moisture and/or corrosion in the unit.  These units are IP67 watertight and should be impervious to water intrusion up to 1m for 30mins.  If there are signs of moisture,

  1. Check the gasket to ensure it has not been squeezed out of the seal.
  2. Check the other fittings for signs of corrosion or looseness

The desiccant is intended to absorb any moisture from the air when the unit is sealed and small amounts of moisture if there is intrusion.  It should be changed annually regardless and as needed if there is intrusion.

  1. To change the desiccant, open the unit and replace the old desiccant pack with a new one.

Cleaning Probe Electrodes

If you find the CF.T has drifted between probes, or is significantly different than 0.486 (see Richardson et al.), or if there are signs of fouling (from permanent installations) then it may be time to clean the electrode surface.  This will often bring the T-HRECS back into calibration without the need to calibrate.

  1. Mix warm water with a small amount of surfactant (a few drops in a bowl of warm water) such as Dawn dish soap.
  2. Rinse probe electrodes in the warm soapy water.
  3. Scrub the inside of the outer electrode and inner electrode with a Q-tip or something similar.
  4. If the electrodes are badly tarnished, soak them in acetone for 2 hours. Make sure the probe’s plastic housing does not contact the acetone.

Tightening the Electrode

  1. Check that the outer electrode is not loose.
  2. If the outer electrode is loose, unscrew it and apply a drop of Loctite Blue Thread Locker to the threads and then screw the outer electrode back on handtight.

Probe Calibration

Before embarking on this endeavour, ensure you try Cleaning and Tightening the electrodes as per above.  If this does not bring the Probe back into spec (i.e. 1% of reference and 0.01%stability or 0.01% standard deviation in 30 points in still water then consider calibrating the T-HRECS.  You will need to be familiar with the Serial Term function of QQ described in the QiQuac Manual-v04-web2.  Instructions for calibration are in the  T-HRECS-M7 Serial Instructions_v0.1.

Update Firmware

We regularly make updates to the QiQuac firmware.  Some recent improvements are:

  1. Add a summary file to each date’s folder for all completed measurements.
  2. Allow the user to adjust the Mass and Pre-BGECT during a measurement.
  3. Allow easy setting of T-HRECS sampling interval from Setup->SDIQ->Set Interval.
  4. Adjust the Y-Axis to zoom in on the BGECT after the peak of the pulse.
  5. Automatically find the start and end of the pulse

To update the firmware, you will need a silver Female DB-9 to USB cable specially modified for the QQ (pins 9 and 7 excavated). The detailed instructions are here: QiQuac Update Firmware_v0.2. You may need to use an older version of FlashMagic.  You will need to contact Fathom Scientific to obtain a .hex firmware file specifically for your unit.

Resetting the QiQuac

On units without a Power Button, i.e. the Push and Turn to Power On units, there are two ways to reset the unit.

  1. Short pins 4&5 as shown in Figure 3
  2. Remove the Battery for units with side battery holder and cap.

To Remove the Battery

On units with side battery holder, after noting the position of the small triangle on the cap, carefully unscrew the cap counterclockwise. The cap should unscrew about 3/4 of a turn.  When screwing the cap back on, it’s important to line up the triangle at about the same location as where it comes loose.  Also note that the cap is the Positive end of the battery.  18650 LiIon batteries have a raised metal end as positive and a flat end as negative.
After removal of the battery, some units require the USB power to be plugged into reset the battery management circuit.
The battery management circuit has reverse polarity protection.

QiQuac Trouble Shooting 

QQ Unresponsive

Power Cycle using the power button on older units.  Carefully remove the battery cap on newer units and remove the battery.  Negative end goes in first.  The QQ may need a USB cable plugged in after removal of the battery to wake the circuit.

Figure 3: DB9. Short Pin 4-5 to reset the QQ.

It is also possible to reset the QQ on newer units (with push-turn on switch) by shorting pins 4&5 on the DB9 connector, shown in Figure 3.

No T-HRECS Signal or Corrupt Signal

Ensure you are getting a signal from both CH0 and CH1 by watching for alternating CH0T and CH1T on the Start Logging main screen. If no T-HRECS Transmission:

  1. Turn the T-HRECS unit on (switch on CH1 and plug in DB-9 on CH0) and check for the following:
    1. On CH1 (Radio) Blue LEDs should light up to indicate battery power.
    2. If Blue LEDs do not flash, then charge the unit.
  2. The Red LED should be on for 30 seconds after the unit is powered up and the Green LED should continually flash for every measurement.
    1. If neither LED has turned on, then the circuit board has likely been disconnected from the battery.
    2. If the Red LED turned on but the Green LED is not flashing, the firmware maybe corrupted. Power cycle the unit to see if this resolves the issue.
    3. If the Green LED is flashing but the Red LED did not turn on, it is likely an issue with the Red LED and not the circuit board.
  3. If the Red and Green LEDs are not working properly on the T-HRECS,
    1. Ensure CH1 unit has power by plugging in USB charge cable.
    2. Ensure CH0 has power by plugging in the DB9 connector.
    3. open the T-HRECS Unit and check connections.
      1. Pull lightly on connections with tweezers to see if any wires are loose.
  4. If the LEDs are working properly, but there still is no signal
    1. Navigate to the Channel’s Serial Terminal.  Access the terminal by navigating from  Setup -> Serial term -> Channel.  Push and Hold for backspace character and to Exit Serial Term. Check for data coming in.
    2. If there is data coming in, but failing to be recognized when Logging, the Device for this channel may have been changed.
      1. navigate to Setup->Select CH0 Device->T-HRECS or Setup->Select CH1 Device->T-HRECS. The QiQuac is able to log Oakton or WTW 300series signals as well as T-HRECS.
    3. The radio in the T-HRECS or QiQuac may have come loose.  Open the T-HRECS and ensure the radio is seated completely.  Open the QiQuac and ensure the radio is seated completely and a piece of tape secures it in place, as shown in Figure 4.

In the case of a noisy, drifting, or jumping signal:

  1. Check to see if the probe’s outer electrode is tight.  It will screw on and off.
    1. If the outer electrode is loose, when back in shop, unscrew it and apply a drop of Loctite Blue Thread Locker to the threads and then screw the outer electrode back on handtight.
  2. Ensure there is no aeration or bubbles in the pool where the probe is.  If in the flask, gently knock the probe’s outer shroud to free any entrapped air.
  3. If neither of these solves the problem contact FSL.

SD Card Error

Figure 4. Use tape to secure both the XBee radio and the SDCard. Replace the CR2032 coin cell or LiIon 18650 main battery as required.

This may manifest with a FAT-SD card error, or it may “Lock up” on the Firmware version screen.  In either case:

  1. Open the QiQuac and check card is pushed all the way into the holder.
  2. We have  been putting a small piece of tape across the SD-Card and holder to ensure it does not get knocked loose, as in Figure 4.
  3. Try a different Class 10 card. It must be formatted as FAT32.  Larger cards might be formatted differently and may need to be reformatted and/or re-partitioned.
  4. If the SDCard is still not working, you could try to format card as FAT32.

 USB not Mounting to Computer

  1. Check if the USB connector is plugged in properly.
  2. Try a different cable in case current cable is damaged. NOTE the grey USB Mini cables supplied with the QQ have been specially modified to increase the plug length.  Standard USB Mini cables will not work.
  3. Inspect the pins at the end of the cable to ensure they’re undamaged. There should be 5 pins.
  4. Try a different desktop machine, preferably with a different OS.
  5. Open the QiQuac and check if the USB connector is connected to the circuit board.

Power Button is Not Working (on older QiQuacs)

  1. Open QiQuac and ensure the battery’s button is directly under the QiQuac Power Button.
  2. If the battery placement has been adjusted, apply crazy glue along the side of the battery to ensure it doesn’t move.

Dial Not Working

  1. Check for material under the dial impeding its travel.
  2. Check for ice buildup in colder conditions.

Incorrect CFT

  1. The calibration standard could be contaminated. Check the calibration standard conductivity. Should be approx. 9.04+/-0.01 mS/cm.
  2. The calibration flask could incorrectly indicate 1L. Check the mass of 1L of water in the flask. It should be 1kg +-0.01kg. Remember to zero the weight of the Flask.
  3. The pipette could be injecting the incorrect amount of calibration standard. Check the mass of a pipette injection. It should be 1.00g.
    1. There is a tool (a plastic wrench) included in the kit to calibrate the pipette.

Date Time reset to 01/01/2000

  1. Possibly a dead clock battery. Open the QQ and replace with CR2032 coin cell, shown in Figure 4.
  2. Possibly poor coin cell connection. Open the QQ, check for play in the contact arm above the CR2032 coin cell.  If it’s not firm, remove the CR2032, press down with a pointed device on the contact arm directly after the bend near the edge. Reinsert CR2032 and check.


The QiQuac can provide many happy years of service, and has for many customers. But it does need some TLC from time to time.  We have designed the QQ to be mostly user-serviceable with a few tools and some care, but there are some tricks, like opening the QQ. If you have any questions or concerns, please contact us.

Contact Us

We offer custom solutions to hydrometric and hydrological problems. We are keen to hear about particular solutions you might require. For more information, or a quote, please contact us using the form below.