AZI Sales/Customer Service 800-528-7411 or 602-470-1414 or [email protected]
Page 95 of 105
10.3. Retained Samples
The weight test and the sodium tartrate test are usually sufficient to satisfy industry
guidelines for quality control in moisture measurement. Some additional checks can be
performed using replicate testing of retained samples. Retained samples, when stored
under airtight conditions, should maintain moisture levels for long periods. Routine
testing of these samples should produce the same results day after day. Retained
samples further verify the instrument's operation on the customer's own product. If
hygroscopic materials are used, the values can change with time and repeated opening
of the sample storage container.
Perform tests using the Test Program for the retained sample (See section
). Results should fall within the established acceptable
range of results for that sample. If results are out of range, repeat the test to verify results
and/or perform standard reference testing to certify the percent moisture value.
11. ROUTINE MAINTENANCE
The MAX
®
4000 requires routine cleaning to keep the test chamber free of excess sample
material. Failure to keep the instrument interior clean reduces its accuracy and
repeatability, as sample material collecting in the test chamber prevents free movement
of the pan support. In addition, sample material collecting on the rim of the heater shroud
prevents the lid from closing completely, causing erratic results. Excess material may
also fall into the system's interior, causing balance problems. Routine cleaning of the test
chamber reduces the likelihood of problems and repairs, extending the life of the
instrument.
11.1. Heat Chamber Cleaning
The chamber interior should be cleaned when needed to eliminate the buildup of sample
material. To clean debris from the chamber’s interior:
•
Use a small paintbrush to remove debris from the balance cover and surrounding
area. Be gentle around the pan support to prevent balance damage.
•
If using a vacuum line or small vacuum cleaner, be careful not to hit the pan support.
Do not clean the balance cover area with a vacuum line or vacuum cleaner
without turning the instrument off and removing the pan support first to avoid
balance damage.
It is recommended to only use a paintbrush on the balance cover
area; then a vacuum can be used to clean the surrounding area.
A compressed air line or canned air is not recommended because
debris may be forced into the system's interior, balance shaft and
balance, and may damage the instrument resulting in costly repairs.
