Analysis and calibration method of after-sales maintenance fault of Sanyo carbon dioxide incubator

Sanyo carbon dioxide incubator after-sales maintenance failure analysis and calibration method:
Calibration of Sanyo Carbon Dioxide Incubator Since the CO2 incubator is greatly affected by the environment and conditions of use, many manufacturers still retain the user's recalibrated components in the product design, generally with calibration and zero adjustment on the panel. Regardless of the type of product, calibration should be performed after the temperature and humidity in the tank have stabilized.
1, temperature calibration:
Some products have been temperature-calibrated before leaving the factory. The calibration components are installed on the control panel inside the box, and the user should not make adjustments. For products with calibration fine adjustment on the panel, close to the culture temperature (such as 37 ° C), take a precision thermometer in the box, wait until the temperature is stable, observe the thermometer indicator value, if the display value is not good, adjust the fine adjustment so that It can be attached.
Temperature calibration steps:
1 Place an accurate glass tube mercury thermometer in the incubator to calibrate the set temperature. At the same time, an accurate thermometer is placed to calibrate the limit temperature.
2 Set the temperature knob to the desired temperature of 37 °C.
3 Turn the limit temperature knob to the maximum. Wait 24 hours for the machine to stabilize.
4 If the temperature has not reached 37 °C, then adjust the temperature knob to 37 ° C, and then wait 24 hours, so that the machine finally stabilized.
5 When the incubator is stable at 37 °C, turn the limit temperature knob counterclockwise until the indicator light of the limit temperature knob is bright.
6 Carefully turn the limit temperature knob clockwise until the indicator light just turns off.
Note: The limit temperature indicator should remain off during normal operation of the machine.
Sanyo Carbon Dioxide Incubator Failure Analysis The carbon dioxide incubator allows cells to grow in an artificial environment. It has been widely used in various tissue and cell culture, tumor, heart disease research, bacterial culture, genetic engineering and IVF. The following three examples of fault phenomena and maintenance methods are introduced to analyze and repair the carbon dioxide incubator failure.
Fault phenomenon 1: No temperature rise, but can display normal temperature fault analysis and elimination: It can display normal temperature, indicating that the temperature detection part is intact, which is a problem of temperature heating control part.
If you don't heat up, you can check it from the following aspects:
1. Is the panel "add water" light on?
2. Whether the over-temperature protection relay (TS1 TS2) is closed;
3. Whether the input voltage of the solid relay TU1 has a driving voltage of DC6V, and whether the (1) pin of TU1 has a voltage of AC100V;
4. Is the heater H1 open?
After inspection, it is found that the output of TU1 is open. Because such type of solid relay is not easy to purchase, other types of solid relays can be used instead. The parameters are DC6V-9V of the drive terminal, current output of the output terminal is >15-20A, and the voltage withstand voltage is >220V. It is appropriate. If you can't buy it, you can also use the method of adding an intermediate relay, but the temperature control accuracy is slightly worse, but it is still feasible as an emergency measure.
Fault phenomenon 2: temperature does not show no temperature rise fault analysis and elimination; ALSCO carbon dioxide incubator temperature controller and temperature display is the temperature control finished product of American Sellden Company, the controller adopts double-sided welding method, the component density is large, and the heat dissipation space is small Therefore, it is easy to cause abnormal damage to the heat generating components.
Such faults occur twice in succession. One time, the 7805 voltage regulator block used for voltage regulation 5V is damaged. After replacement, in order to prevent damage again, a small aluminum piece is fixed on the heat dissipation part, and the heat dissipation condition is improved; the other phenomenon is the same as above. After inspection, it is the primary disconnection of the power transformer. Because such transformer (primary 100V secondary 6V) is not easy to buy, it can choose the domestic primary 220V, secondary 12V or double 6V power 5W~10W finished transformer according to the principle of transformation ratio. Replacement, if you choose a double 6V transformer, you need to float the tap, use the wire to find a suitable position to fix.

Symptom 3: The CO2 concentration is too high, about 2% to 5% higher than the set value, and unstable.

Fault analysis and elimination: factors causing high and unstable CO2 concentration
1. The filter is clogged;
2, the pipeline leaks;
3, CO2 sampling to detect water in the pipeline;
4. The sampling pump speed is too low, and the sampling speed is too low, which makes the detection system unresponsive.
In the above cases, the CO2 solenoid valve cannot be closed immediately after the CO2 concentration shows that the set value is reached. In this case, the fault was found to be low, and the pump was checked according to the manual. The pump speed was found to be low. Open the upper cover and find the VR3 potentiometer. Turn it counterclockwise and observe the flow meter (0.8~1.0L/min). ).
If there is no flow meter, it can also be adjusted according to the action of the valve. When the flow rate is suitable, the valve should be closed immediately after the concentration reaches the predetermined value. If the flow rate is too small or too small, it is not conducive to detection. If the detection sensitivity is high, it is easy to The water in the humidity tank is drawn into the pipeline, causing a fault of abnormal concentration. The detection system of the too small detection system is slow and cannot be eliminated. Generally speaking, after several careful observations and adjustments, the above requirements can be met.
Fault phenomenon 4: When the concentration reaches the set value, the intake valve is closed, but the concentration continues to rise. Fault analysis and elimination: the solenoid valve can be closed immediately after the concentration reaches the set value, indicating that the basic normal solubility of the CO2 analysis and detection system continues to rise. There are several possibilities:
1. The valve gasket is aging or contains foreign matter, causing the valve to be closed tightly;
2. The pressure of the CO2 input to the pressure divider is too high. Generally, the pressure of the partial pressure gauge should be less than 0.3kg/cm2. If the pressure is too large, the CO2 will still seep into the tank after the valve is closed.
The fault of this case was found to be aging of the rubber seal of the incubator valve. The heating method was used to heat the seal ring to restore the compressibility, and then a little silica gel was applied to solve the problem.
Fault phenomenon 5: CO2 shows zero deviation fault analysis and elimination: There are several possibilities for such faults:
1. The pipeline is leaking or blocked;
2. The CO2 measurement bridge circuit is unbalanced due to the change of the long-term working component parameters. The inspection method is to close the main valve of the CO2 cylinder and open the incubator door. Observe the CO2 display value after about 2 minutes.
If CO2 shows that the solubility is not at zero, it means zero deviation. At this time, the ZERO fine adjustment on the panel can be adjusted. If the adjustment is not enough, the upper cover can be opened to find VR1 (CO2 zero point coarse adjustment) on the PB1 circuit board, if it cannot be adjusted. Consider the aging of the CO2 probe and only replace it.
Fault phenomenon 6: Analysis and elimination of large noise: The noise is generally from the air pump or fan motor. Due to the long-term work of the carbon dioxide incubator, the motor is often short of oil, causing serious shaft hole damage and causing noise. This model uses a fan motor. More faults.
If the shaft hole is lightly damaged, it can be solved by adding a proper amount of oil after cleaning. If the friction is serious, only the motor can be replaced. This motor is not easy to purchase on the market. You can use the fan motor used in the imported refrigerator instead. The effect is very good, but it should be noted that the power of the refrigerator motor is 220V, and the original motor is 100V. Therefore, the old motor lead can be disconnected, and the new motor can be directly connected to the input end of the 100V transformer.

Aluminum Foil Net

Aluminum Foil Net,Knitted Aluminum Heat Shield,Full Shading Reflect Net,Insulating Aluminum Foil Mesh

Changzhou Green Nets Co.,Ltd. , https://www.czglnets.com