Basic rules to be followed when maintaining the in

Basic rules to be followed when maintaining the instrument

basic rules to be followed when maintaining the instrument

1 Once rule

when the system fails, you can tentatively change some states, one parameter at a time. Some simple change steps may solve the problem

2. The secondary comparison rule

has identified the fault location or determined the solution to the fault before starting the maintenance. In other words, you have found the right solution before you start. For example, during the sampling process, it is found that the static stiffness of the internal standard reflects that the peak value of the support capacity of the shock absorber has become low. You can repeat the sampling to see how the repeatability is. If it is accidentally reduced, whether there are bubbles in the quantitative tube. This rule can be used to examine the situation after the system changes. After the flow is replaced, the standard can be injected twice before the technical introduction of the front and back door and tail support pressure tester to check the stability of the retention time and the stability of the chromatographic peak. If there are redundant peaks in gradient elution, it can be eluted once without load gradient (is there really a problem?), Using this rule can avoid unnecessary changes and determine corrective measures as soon as possible

3. Replacing the rule

replacing suspicious parts with good parts is the best way to find faults. If you suspect that the detector causes noise, replace it with a rotor less vulcanizer detector with good performance. If the fault is eliminated, there is a problem with the replaced detector. The scale of application of this rule varies from changing the whole part to changing the integrated block on the printed circuit board

4. Replacement rule

this rule is applied together with the replacement rule. The situation has not been improved after the good part replaces the suspicious part of the melt flow rate tester, and the original part should be replaced. This will minimize the maintenance cost and prevent the backlog of used parts. This rule applies only to a single fault. The replacement principle is not applicable to the following situations:

(1) the new parts have been damaged when they are removed (such as the pump sealing gasket)

(2) low component price (such as column lined filter)

(3) risk of damage when reinstalling the original parts

(4) parts replaced regularly

5. The reference condition rule

usually has two reference conditions: ① standard reference conditions; ② Test reference conditions

standard reference conditions are also called standard test conditions, which are easy to verify from one system to another and from one laboratory to another. The data measured with this condition is helpful to identify the problem of extending the service life between the actual test and the system. If the system pressure rises under certain test conditions, but the pressure is normal under standard conditions. This shows that the abnormal system of the melt flow rate tester is caused by the changes in the laboratory. 1.3 the design of the experimental machine should be reasonable in structure, beautiful in appearance, simple in operation and easy to maintain