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    Home > Active Ingredient News > Drugs Articles > How to maintain UV detector

    How to maintain UV detector

    • Last Update: 2019-02-20
    • Source: Internet
    • Author: User
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    The ultraviolet absorption detector is called ultraviolet detector for short It is designed based on the principle that solute molecules absorb ultraviolet light Its working principle is Lambert Beer law, that is, when a beam of monochromatic light passes through the flow cell, if the flow phase does not absorb light, the absorption a is directly proportional to the concentration C of the absorption component and the optical path length L of the flow cell The maintenance of UV detector is also very important at ordinary times The following small edition introduces how to maintain UV detector: circulation pool maintenance for slightly polluted circulation pool It can be cleaned online by circulation pool For heavily polluted circulation tanks, online flushing generally does not work The flow cell assembly should be removed from the instrument for cleaning The steps are as follows: loosen the fixing screw on the upper end of the sample flow cell Take out the flow cell components, remove the joints at the inlet and outlet respectively, and then screw out three screws to fix the window plate and take down the stainless steel plate, then take down the two quartz window plates of the flow cell Pay attention not to lose the plastic King seal ring of the contact part between the window piece and the circulation pool body Put the window piece and the flow cell body into two beakers with methanol respectively, and wash them with ultrasonic for 20min If the pollution is especially serious, the ultrasonic can be continued for 20min after the methanol is replaced; the window piece can also be cleaned by dipping the absorbent cotton in the methanol Then ultrasound After cleaning, control the dry solvent, put it in an 80 ℃ oven, take it out after 30 minutes, cool it to room temperature, and then assemble it When assembling the flow cell assembly, it should be noted that the tightness of the three screws should be based on the principle of no leakage after the flow cell enters the mobile phase: the three screws on the flow cell must be tightened crosswise, otherwise it is easy to cause leakage: if the three screws are tightened too tightly, the quartz window will be broken Clean the exit window of monochromator exit slit After drawing out the drawer, open the photoelectric detection head, and loosen the screw on the upper end of sample and reference pool Take out the sample cell and reference cell Then take out the window piece behind the sample tank and reference tank Wipe the window pieces with Yi ether respectively When the solvent evaporates, it can be reduced Cleaning of photodiode window piece of photoelectric detection head: pull out the drawer of control box, open the detection head, observe the window piece of sample and reference photodiode, and scrub with Yi ether After the solvent on the window plate evaporates, close the photoelectric detector head assembly Maintenance of deuterium lamp proper use and maintenance of deuterium lamp can prolong its life The specific method is: after replacing the deuterium lamp, the deuterium lamp counter should be cleared to correctly display its use time If the instrument is on, but no analysis is made for a period of time, the deuterium lamp can be turned off temporarily to extend its service life Clean the window of deuterium lamp with methanol every half a year to prevent dust from attenuating light energy Note: if the wavelength used is short, such as 200-210 nm, the life of the deuterium lamp is shorter than that of the longer wavelength The instrument should be cleaned once every three years to ensure the performance of the instrument and reduce the occurrence of instrument failure This maintenance needs two people to cooperate Take out the control box from the instrument, first clean the dust inside the instrument with a small brush, and then let the vacuum cleaner suck it away immediately In particular, the cooling fan under the deuterium lamp accumulates a lot of dust and dirt, which needs to be cleaned repeatedly If the deposited dust contains oil dirt, it is difficult to clean it with a small brush At this time, it can be cleaned with a absorbent cotton dipped in ethanol [2] Cleaning in monochromator: unscrew the screws on the top of monochromator and open the top cover of monochromator Purge grating and concave mirror with dry nitrogen Please note that it is not allowed to wipe the grating with mirror paper If it is found that the concave mirror in the monochromator is dirty, it can not be cleaned by nitrogen purging It can be washed with neutral detergent and then washed with deionized water If there is a large area of mould on concave mirror, it can only be replaced with new one Monochromator grating motor mechanical drive maintenance grating motor mechanical drive consists of motor, screw rod and guide rod After 3 years of operation, the lubricating oil of the mechanical drive part dried up, and a layer of oil was formed on its surface Make the motor stress increase, serious will cause motor drive circuit damage Maintenance steps: take out the control box and the top cover of monochromator Use anhydrous alcohol or acetone to clean the remaining oil stains on the screw rod and guide rod After they are dried, drop several drops of light lubricating oil on the screw rod and guide rod respectively Rotate the motor repeatedly to make the lubricating oil evenly distributed on the surface of the screw rod and guide rod.
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