Delay Path

Dewar Precautions

Parts and accessories are located on the Micromeritics web page.

A delay path is used to reduce the perturbation (disturbance) of the gas flow caused by injections of gas through the septum.

Delay path tube

 
  1. On both ends of the tube, insert the retaining nut (knurled end first), the ferrule (small end first), and O-ring. Leave the O-rings close to the top of the tube.
  1. Retaining nut (insert knurled end first)
  2. O-ring
  3. Ferrule (insert small end first)
  1. Insert the open ends of the tube into the delay path ports under the upper panel of the analyzer.
  2. Press the tube up into the analyzer until it comes to a stop. Hold the tube in place and tighten the retaining nuts by hand. Tighten the nuts only enough to hold the tube securely in place and prevent leaks.
  Do not overtighten the retaining nuts. A sufficient seal is achieved when the fittings are finger tight.
  1. Fill the Dewar with the appropriate coolant.

Change or Clean the Delay Path Tube

Occasional cleaning of the tubes is required.

  1. If a Dewar is around the delay path tube, raise the Dewar slightly and remove the Dewar shelf. Then remove the Dewar. Allow the tube to warm to room temperature.
  Depending upon the state of the analyzer, the tube fittings may be hot. Use caution. Use the cotton gloves provided in the accessory kit when handling heated surfaces. These cotton gloves are not intended to protect hands when heated surfaces are above 60 °C.
  1. To remove the tube, loosen the retaining nuts on the port fittings.
  2. Remove the tube, retaining nuts, ferrules, and O-rings.
  3. Clean the tube by flushing with isopropyl alcohol (IPA). Dry the tube in an oven or by blowing compressed air or nitrogen through it before replacing it.
  1. Inspect the O-rings for cracks or other damage that might cause leaks. If the O-rings are cracked or damaged, replace them before reinstalling the tube. Otherwise, clean, dry, and re-install the O-rings.
  Use only Kalrez O-rings. Kalrez is rated for both chemical and temperature suitability in this application. O-rings of other materials could burn, melt, or decompose.
  1. On both ends of the tubes, insert the retaining nut (knurled end first), the ferrule (small end first), and O-ring. Leave the O-rings close to the top of the tube.
  Do not over tighten the retaining nuts. Doing so may damage the O-rings. Finger tight is sufficient.
  1. Hold the tube in place and tighten the retaining nuts. Tighten the nuts only enough to hold the tube securely in place and prevent leaks.