After the injection valve is switched to the Inject position, hold it there for a period of time to allow the mobile phase to flush the sample loop sufficiently to ensure greater accuracy without having to flush the sample loop separately. This chromatograph-controlled flush is obviously better than manual flushing. Note: The volume of mobile phase required for flushing is at least 10 times the volume of the injected sample. For example, if you take 20 μL of sample into a 100 μL sample volumetric tube and the flow rate of the current phase is 1 mL / min at this point, you will need to maintain at least 12 s at the injection site, ie 20 μL × 10/1000 μL · min -1 = 0.2 min = 12s. After the sample tube is fully rinsed, it can be rotated back to the sample position (Load), or it can remain in the sample position until it can be switched back to the sample position before the next sample. When switching back to the sample position, remove the sample or trace sample syringe from the injection valve. To prevent cross-contamination, it is not necessary to flush the injection needle injection port after each injection under normal conditions. The patented direct-injection port in the injection valve allows the front end of the injection needle to connect directly to the end of the sample tube, leaving no room for sample residue. This will not result in the last sample remaining in the sample tube at the next injection. However, during insertion or removal of the needle, traces of the sample deposit in the needle seal area. Precision measurements show that this residue has 1nL ~ 10nL. This shows that into the 20μL sample, will remain 0.005% ~ 0.05%. Flush the needle inlet after each injection to flush the residue clean. The process of flushing the needle introducer is as follows: Set the flow rate of the mobile phase to 0.1 mL / min to 1 mL / min. Connect the syringe introducer wash head (Rheodyne part number 7125-054) to a relatively bulky syringe Use a large number of mobile phases to clean the needle introducer only at the injection site. The liquid entering the injection valve thus bypasses the sample loop and is discharged from the sample overflow tube 5 #. This procedure allows for thorough cleaning of the needle introducer, guide, needle introducer and needle seal. The use of syringe fully inserted flushing method, you can not fully clean the surface of the above part. When the needle is inserted into the needle introduction port at the sampling position, the needle pushes a small amount of sample liquid (left behind from the previous injection needle introduction tube) in the injection needle seal into the sample tube. When the sample liquid and mobile phase composition is different, and at the same time using a partially filled tube injection mode, the sensitivity of the detector may appear strange peaks. So rinse the needle is best to use mobile phase rinse. If serious cross-contamination has been observed, check for the following: i. The length of the needle used is not enough (the length of the needle is at least 5 cm) and the end of the needle can not reach the surface of the stator. Ⅱ. The injection needle is not fully inserted into the needle introducer. Ⅲ. The contaminants in the needle introduction port or the shavings sealed by the needle seal make the end of the injection needle unable to contact with the stator surface. If you do not consider cross-contamination, injection of 10 or 20 times per injection is best to wash the needle inlet, this can ensure that the needle into the tube filled with fluid. Flushing the injection needle or diluting the sample that contaminated this area while the needle is inserted or removed also allows fluid to fill the injection port and the sample spill port # 5 to prevent air from entering the sample tube.

Floor Grinding Machine have 2 types: 

1. Floor Grinder with vacuum cleaner, working no dust. 

2. Floor Grinder with water tank, cau working for floor grinding and polishing. 


Floor grinding, coarse concrete floor burnishing, old epoxy floor renovation, sealed curing floor polishing, marble ground maintenance.

1. floor industry :epoxy , wear-resistant floor, curing floor,penetrating floor,artistic floor ect.
2.stone industry: polishing and maintenance for various stone such as marble granite.

Main scope: Concrete Grinding machines, Floor Polishing Machines, Road Line Marking Machines, Truck Cranes, Road Rollers, excavators, Concrete Leveling Machines, Power Trowels and other Construction machinery .

Jining oking tec co.,ltd, established in 2010, is a professional manufacturer engaged in the research, development, production, sale and service of Concrete Grinding machines, Floor Polishing Machines, Road Line Marking Machines, Truck Cranes, Road Rollers,  Excavators , Concrete Leveling Machines, Power Trowels and other Construction machinery .

We are located in Jining city,Shandong province with convenient transportation access. Dedicated to strict quality control and thoughtful customer service, our experienced staff members are always available to discuss your requirements and ensure full customer satisfaction.

In recent years, we have introduced a number of advanced production equipment, and also have an excellent production team and a complete quality assurance system to ensure that each batch of goods is delivered to customers in a timely and high quality.

We also have an excellent management team, experienced technical staffs and professional sales team to solve all problems you encountered before and after sales. In addition, we have obtained I S O 9 0 0 1:2 0 1 5 certificates. Selling well in all cities and provinces around China, our products are also exported to clients in such countries and regions as United States, Europe,Australia, Southeast Asia,Russia,the Middle East,Africa. We also welcome OEM and ODM orders. Whether selecting a current product from our catalog or seeking engineering assistance for your application, you can talk to our customer service center about your sourcing requirements.

OK-300 Floor Grinding Machine

OK-300 Floor Grinding Machine

Floor Grinding Machine,Marble Floor Grinding Machine,Concrete Floor Grinder,Concrete Grinding Machine

Jining Oking Tec Co., Ltd. ,