The QJZY-1 fully automatic interfacial tension tester measures the surface tension (liquid gas phase interface) of various liquids and the interfacial tension (liquid-liquid phase interface) of mineral oil and water in accordance with the requirements of GB6541-86 "Petroleum Product Oil Water Interface Tension Measurement Method" (Circular Ring Method). The instrument adopts a large screen dot matrix LCD display, full Chinese character menu prompts, high degree of automation, reliable operation, good repeatability, and extremely simple operation. Simply press the menu prompts after turning on the machine to complete all experiments. The instrument has automatic lifting and lowering of the sample stage, clock control, power-off storage, and automatic calculation of interfacial tension values.

Fully automatic interface tension meter QJZY-1Technical parameters:

Applicable standards: GB6541-86 ISO6295-1983

Measurement range: 0~200mN/m

Movement speed: 0.3~0.4mm/s

Sensitivity: 0.1mN/m

Accuracy: ± 0.2mN/m

Applicable temperature: 10-40 ℃

Applicable humidity: ≤ 80%

Power supply: AC 220 ± 10% 50Hz

Power consumption: 45W

Dimensions: 185 × 310 × 380

Working principle

The working principle of this instrument is to apply the high-frequency induction small displacement automatic balance measurement system to the torsion balance. When the force acting on the platinum ring changes, the balance rod connected to the platinum ring will produce displacement in the two eddy current probes, causing the inductance generated in the two eddy current probes to change. This will cause the differential transformer to lose balance, and the input signal of the differential amplifier in the circuit will also lose balance. After amplification by the amplifier, an electrical signal that changes with the force on the platinum ring will be output. This signal is sent to the microprocessor for processing, and the actual tension value of the tested sample will be automatically calculated according to international GB6541.

structure characteristics

1. LCD display 2. Sample cup

3. Zero point fine-tuning 4. Gain adjustment (full-scale)

5. Platinum ring 6. Sample stand

7. Keyboard 8. Machine foot: Adjust instrument level

Installation and horizontal adjustment

Place the host on a stable platform without wind flow, as shown in Figure 2, unscrew the two fixing screws on the back of the instrument, remove the upper top plate, and install the control magnet, ring frame rod, and platinum ring in the position shown in Figure 3 (the platinum ring should be inserted into the ring frame rod first, and the outer flame of the alcohol lamp should be burned and cleaned before installation. Note: Do not touch the burned and clean platinum ring with your hands). Adjust the three machine legs so that the level bubble on the sample tray is centered, then place the top plate back in its original position and fix it with screws.

• instrumentation

After connecting the power, the instrument displays the startup interface. After about 5 seconds, it will automatically enter the main menu interface.

1. Weight calibration: According to the formula: F=mg/2L L=2 π r0 (where r0 is the radius of the platinum ring)

After unboxing the instrument, weight calibration should be performed to calibrate the torque balance of the system. First, place a small piece of paper not exceeding 5mN on the platinum ring to hold the weights. At this point, first press the button corresponding to "zeroing", and the display screen will show "zeroed", with the purpose of deducting the weight of the paper. Then press the button corresponding to "calibration", and you can use tweezers to place the weight on the platinum ring to calibrate the instrument.

100mg weight ----------------------------------------------------------------------±0.2mN

500mg weight -----------------------------------------------------------------------±0.2mN

1g weight -----------------------------------------------------------------------±0.2mN

In general, the range used by the user is within 100mN, and a weight calibration check of 1g is sufficient. In special circumstances, it can be calibrated to full range.The actual situation is that when calibrating weights, users only need to calibrate one point to ensure full range linearity.If the calibration value of this instrument is too large or too small, it can be fine tunedOn the right side of the instrumentGain potentiometer. Generally, satisfactory results can be obtained after 2-3 attempts.

1.2 Press the "Settings" button to enter the main settings menu

1. Parameter setting:
2. 2.1 Sample density: according to“→”Move the cursor with the key, press“↑”Press the key to modify the data, enter the sample density, and after entering the data, press "confirm" to save the parameters.

2.2 Other parameter settings are the same as above.

After setting the parameters, press the "Return" button to return to the main menu step by step.

1. Pure water calibration

3.1 Preparation work (in accordance with Article 4.1 of GB6541)

Clean the sample cup with petroleum ether, then wash it with ethanol and water separately, and soak it in hot chromic acid solution to remove oil stains. Finally, rinse it with water and distilled water. If the sample cup is not to be used immediately, invert it on a clean cloth, clean the platinum ring with petroleum ether, rinse it with butanone, and then heat it in the oxidizing flame of an alcohol lamp.

Attention: Cleaning the platinum ring should be done by removing it from the ring frame rod. When removing and installing the platinum ring, be sure to turn off the instrument power. After installing the platinum ring, make sure that each part of the platinum ring is on the same plane

Add pure water to the sample cup until the bottom mark is reached, then press“↑”Key, the sample stage starts to rise until the platinum ring is submerged in water. When calibrating pure water, the density of the heavy liquid is 1.000 for water and 0.023 for air.↓

3.3 Press the "Start" button, the instrument will automatically delay for 30 seconds, and the sample stage will automatically descend to start detecting the interfacial tension between pure water and air. As the platinum ring gradually moves awayinterfaceThe tension value gradually increases,When the maximum value is detected, tension valuealsostartslowlyReduce, in this process,causeinstrumentmicrocomputerautomaticlockThe maximum value is obtained, and then automatically converted according to the standard formula to obtain the interfacial tension value, which is locked and displayed on the LCD screen.

According to Article 5.3 of GB6541, the calibration value of pure water should be between 71 and 72 millinewtons per meter. If there is a difference, please repeat Articles 1.1 and 3.1 of this manual and burn the platinum ring on an alcohol lamp until clean.

After completing the calibration of pure water, press the "Exit" button to return to the higher-level menu.

4. Sample testing

4.1. Firstly, modify the density of heavy and light liquids. The sample testing is the same as above, except that3.After 2 steps of operation, lift the sample table up and gently add the sample to the water surface with a beaker, with a thickness of about 1cm, generally exceeding the mark on the sample cup. Then follow step 3.3 to proceed.

1. Time adjustment: Same as modifying parameters.