Changing pump tubing is a periodic maintenance item for Isco Automatic Samplers. The need for pump tubing replacement varies with the frequency of sampling, the suction line length, purge intervals, rinse cycles and the model of sampler. Here are a few tips:
All current Isco samplers have a counter that will record pump counts (a subset of revolutions) and display a warning on the screen indicating when it is time to change the tubing. Once the tubing is changed you can reset the counter and choose the number of pump counts for the next alarm. For Isco 3700, 3710, GLS, and Glacier model samplers the recommended interval is 500,000 pump counts. For Isco 6700, 6712, 4700, and Avalanche model samplers the interval is 1,000,000 pump counts. Using the change pump tubing counter helps prevent the loss of samples due to wear or failure of the pump tube.
The increased life of the pump tubing in the newer model samplers is due a higher speed pump and specially cured slightly thicker pump tubing. It is important to make sure you use the appropriate pump tubing. The tubing for these newer samplers is cut to a specific length for the model of the sampler and has blue bands that are designed to fit into grooves in the sampler pump housing. Due to the design of the higher speed pump it is critical that the tubing is seated in these grooves for proper pump performance and tubing life.
All Isco samplers manufactured since 1992 include a liquid detector that senses pressure through the pump tubing and allows the sample to know when liquid has reached the sample pump. To ensure proper operation of the liquid detector, make certain that there is no grit or debris between the pump tubing and the detector, and that the detector cover is secured. Do not over tighten the knob on the cover, as this can cause the cover to crack. Hand tight is all that is required.
If you have any questions on the type of pump tubing your sampler needs or any other questions on sampler maintenance please contact one of our technicians.