News > Water Quality Instruments and How to Store Them Correctly

Water Quality Instruments and How to Store Them Correctly:

Water quality instruments are seasonal as over the course of the winter months, data collection must stop due to the conditions in rivers and lakes. Until the spring when water quality testing can continue, all water quality equipment must be stored safely. What is the best way to store the water testing equipment for a long period of time?

The way you store your water quality instruments can prolong the life of your equipment and make your job easier when water quality testing can resume in the spring.

Instruments and Handhelds:

Firstly, any batteries from a water quality instrument or handheld device must be removed. The battery compartment o-rings need to be check for nicks, dry rot, pitting, or any other damage. These need to be replaced if there are any damages, apply a small bit of Krytox lubricant to the o-ring. Check for corrosion in the battery compartment and if any is detected, clean the corrosion away and check for damage. If damage is detected, send the instrument or handheld unit back for repair. It is important that the batteries are not reinstalled in the instrument to prevent any battery leaks damaging it.

The instrument needs to then be cleaned following the procedures in the instrument’s manual ensuring that all communication ports and empty sensor ports are capped or plugged. Hard to remove debris may still be on the instrument so it would require overnight soaking in soap and water or a diluted vinegar solution, ensuring that connectors and ports are capped and plugged. After cleaning or soaking, the sensors and instruments need to be removed. The instrument should be allowed to dry but not the sensors. Check the instrument after it has been cleaned for any signs of damage or wear.

The types of sensors that are normally connected to the sonde means that storage of the instrument will vary. Some of the sensors require that they are stored in a solution and others can be stored dry.

Water Quality Sensors:

All sensors have a particular storage need but they all share a common need to be cleaned and inspected before being stored correctly. The sensors all need to be cleaned with soap and water as well as gently scrubbed. Soaking may be needed for additional contamination, so it is recommended that the sensors are attached to a sonde for soaking so that the connectors are protected. There are additional cleaning requirements can be found in the manual of the sensor. Follow the below storage procedures to ensure that your sensor is ready for the next monitoring season.

Temperature/Conductance, Turbidity, Total Algae, and FDOM:

Sensors can be stored wet or dry and if it is not going to be attached to an instrument, a connector cap must be attached. The sensor needs to be stored in an airtight container and if attached to the instrument, it can be stored safely in any solution that the other sensors will require. If sensors attached to the instrument can be stored dry, simply attach the guard and dry calibration cup. Store it in an airtight container with the instrument in a carrying case or dry location out of sunlight.

pH/ORP:

The pH/ORP sensors should never be stored dry, it is always to be stored wet. The recommendation for this sensor is that it is removed from the instrument and stored in the storage container it was originally shipped in. It should be stored in a storage medium of pH 4 solution. Over the winter season, be sure to check that there is still solution inside the container and refill when necessary. In case the sensor goes dry, there is a rehydration procedure in the manual, but it could still be too late as the sensor may be irreparably damaged. Sensors should be stored upright in their container in a location that is out of direct sunlight.

Dissolved Oxygen:

The Dissolved Oxygen sensor should never be stored dry either. It would be ideal for this sensor to remain attached to the instrument it is typically connected to. The calibration cup should get filled with water, the sensor needs to be submerged and the calibration cup must be tightened to the instrument preventing as much evaporation as possible. The instrument then be stored in a secure location to ensure that the sensor is fully submerged in water. These sensors need to be checked to see if they are staying wet throughout the winter and need to be refilled when necessary. If they go dry, there are rehydration steps to follow in the manual, but the sensor gain may be affected compared to that recorded before the storage period.

Cables:

The maintenance of field cables that connect to handheld devices are easy to care for.

The first step is to clean off any debris from the cable and verify that the integrity of the cable is still intact by checking the length for damage. The cables are most vulnerable to damage at the connectors, this is where most of the attention should be focused. The connectors should be inspected thoroughly for any nicks or tears and all contamination needs to be removed using soap and water.

Krytox grease must be applied thinly to the connectors to keep them from drying out and cracking once stored away. When the cable is dry, if it can remain attached to the instrument and handheld normally paired with, that would be ideal; then, place the assembly inside an airtight storage container away from direct sunlight. If this is not possible, attach the connector storage caps to the cable it was initially shipped with to either end of the cable over the connectors and place the cable in an airtight storage container away from sunlight.

Flying lead cables can be left out in the field over the winter or pulled from site for storage in the lab like the rest of the instruments. If the cable cannot be removed from the field, first check the exposed portion of the cable for damage and clean off contamination. Attach the storage cap on the end of the cable that may have been exposed to moisture and completely wrap the end with electrical tape to keep out excess moisture. If you use a vented flying lead cable, replace the old desiccant with fresh and cap the end of the cable to keep the tube dry.

If the cable can be removed from the field, be sure to check the entire length for damage and clean off the contamination and debris with soap and water. Apply a small bit of Krytox grease to the connector that would normally attach the sonde and then place the red storage cap on the end. The exposed wires on the other end are to be bundled together and wrapped with electrical tape or bubble wrap to keep the ends from being damaged. Once the cable is dry, it is okay to be placed in airtight storage and kept out of the sunlight. If it is a vented flying lead cable, the desiccant should be replaced with a fresh desiccant and the ends of the cable need to be capped. The entire cable should then be placed into an airtight container and surrounded by desiccant to ensure that no moist air can enter the cable.

When using a polarographic or galvanic sensor, it should always be stored dry for long-term storage (>30 days). The membrane cap needs to be removed from the instrument and the sensor needs to be cleaned in freshwater. It needs to then be dried completely and a new membrane cap is to be installed over the dry electrodes to protect them. The storage membrane cap is not the same as the one used for field sampling – a new membrane cap with electrolyte solution needs to be installed before returning to the field.

ISE’s:

 Ion Selective Electrodes should never be stored dry or be fully submerged. These sensors must be removed from the instrument and stored in the storage containers they originally came in. The medium that the sensor needs contained in is plain tap water. It is important that this sensor is not stored in conductivity standard, pH buffer, salt water, or any other medium with significant conductivity as these will damage the sensors. This medium needs to be checked and refilled if necessary, over the period of winter. If the sensor is to go dry, there is a rehydration procedure to follow in the manual, but it may not fix the damage already done. The sensors need to be stored upright in their container out of direct sunlight to limit as much evaporation as possible.

Central Wiper:

It is important that your central wiper is taken care of correctly during this time as it is what helps prevent fouling during the field season. It is recommended to get an annual service of the central wiper to replace the o-ring inside of the sensor that cannot be changed outside of a repair centre.

Cables:

The maintenance of field cables that connect to handheld devices are easy to care for.

The first step is to clean off any debris from the cable and verify that the integrity of the cable is still intact by checking the length for damage. The cables are most vulnerable to damage at the connectors, this is where most of the attention should be focused. The connectors should be inspected thoroughly for any nicks or tears and all contamination needs to be removed using soap and water.

Krytox grease must be applied thinly to the connectors to keep them from drying out and cracking once stored away. When the cable is dry, if it can remain attached to the instrument and handheld normally paired with, that would be ideal; then, place the assembly inside an airtight storage container away from direct sunlight. If this is not possible, attach the connector storage caps to the cable it was initially shipped with to either end of the cable over the connectors and place the cable in an airtight storage container away from sunlight.

Flying lead cables can be left out in the field over the winter or pulled from site for storage in the lab like the rest of the instruments. If the cable cannot be removed from the field, first check the exposed portion of the cable for damage and clean off contamination. Attach the storage cap on the end of the cable that may have been exposed to moisture and completely wrap the end with electrical tape to keep out excess moisture. If you use a vented flying lead cable, replace the old desiccant with fresh and cap the end of the cable to keep the tube dry.

If the cable can be removed from the field, be sure to check the entire length for damage and clean off the contamination and debris with soap and water. Apply a small bit of Krytox grease to the connector that would normally attach the sonde and then place the red storage cap on the end. The exposed wires on the other end are to be bundled together and wrapped with electrical tape or bubble wrap to keep the ends from being damaged. Once the cable is dry, it is okay to be placed in airtight storage and kept out of the sunlight. If it is a vented flying lead cable, the desiccant should be replaced with a fresh desiccant and the ends of the cable need to be capped. The entire cable should then be placed into an airtight container and surrounded by desiccant to ensure that no moist air can enter the cable.

Want to find out more?

If you are interested in finding out more about water quality and how to clean the instrumentation correctly, please contact a member of our sales team today, they will be happy to help.