The instrument has a waterproof shell, and the mechanical buttons provide high reliability, high touch and sound notification functions. It uses a single 9V dry battery as the power supply, and the calibration data is stored in the EEPROM memory for a long time, so it does not need to be calibrated again when it is used next time. .
3020M can be connected with four-wire conductivity electrode (K=0.475) or two-wire conductivity electrode (K=0.1). 3020M also includes automatic switching test range, automatic temperature compensation, long battery life and 50/60HZ AC noise rejection capability, this instrument is suitable for field and laboratory.
battery replacement
When the "BAT" on the LCD flashes, it means that the power is insufficient. It can be used for about 1 hour and needs to be replaced with new battery. The steps to replace the battery are as follows:
1. Remove the two screws using a screwdriver to remove the battery cover. (Please refer to Figure 1)
2. Take out the old 9V battery and install a new one. When replacing, please pay attention to the correct .
3. Put back the waterproof ring and battery cover, and tighten the two screws just taken out.
Steps
A. Preparation of standard solution
Suitable standard solution preparation powders need to use commercial or research grade powders. The following are the preparation methods of three concentrations of standard solutions. Users can use them to calibrate the conductivity .
1. 14.94uS standard solution (25°C): Accurately measure 100ml of 147uS standard solution and dissolve it in 900ml of distilled water.
2. 147uS standard solution (25°C): Accurately measure 100ml of 1413uS standard solution and dissolve it in 900ml of distilled water.
3. 1413uS standard solution (25°C): Accurately weigh 0.746 g of research grade KCL and dissolve it in 1000ml of pure water.
4. 147uS standard solution (25°C): Accurately measure 100ml of 1413uS standard solution and dissolve it in 900ml of distilled water.
5. 12.90mS standard solution (25°C): Accurately weigh 7.4365 g of research grade KCL and dissolve it in 1000ml of pure water.
6. 111.9mS standard solution (25°C): Accurately weigh 74.264 g of research grade KCL and dissolve it in 1000ml of pure water.
[Note: You can store leftover unused standard solutions in airtight containers at temperatures below 4°C for a week. If you have doubts about the accuracy of the standard solution, please prepare a new standard solution. ]
B. Conductivity Calibration
The correction step includes five steps: correction of TDS coefficient, conductance cell constant, temperature coefficient, reference temperature and conductivity value. The detailed steps are as follows:
1. Connect the conductivity electrode 3020P (K=0.475) or 109P (K=0.1) to the input . After pressing the switch key to turn on the machine, the host will display "CELL" and the cell constant of the conductance electrode stored in the microprocessor . (factory set to K=0.475)
2. When the temperature reading is stable, press the “CAL” key to enter the calibration mode. "CAL" will be displayed on the LCD. Pressing the "MODE" key will continue to display the following parameters.
TDS
The TDS total solid dissolved amount is obtained , and the factory setting value is 0.65. You can use the up and down keys to adjust the TDS factor value , and the adjustment range is 0.30~1.00. Press the "ENTER" key to save the new set value, or press the "MODE" key to exit the storage and enter the "Constant" interface.
constant
用上键和下键选择电极常数：“C0.5” 或者 “C0.1” ，按“ENTER”键储存所选择的常数值，机器将自动进入下一个校正参数；或者按“MODE”键退出储存，上次存储的常数值将被保留，并自动进入“温度系数”校正界面。
温度系数
本仪器是用温度系数计算具有温度补偿的电导率值的，此温度系数默认值为1.91%. 你可以用上键和下键调节这个温度系数值，调整范围是0.00~4.00%，按“Enter” 键储存新的设定值，或者按“Mode”键退出储存，进入“参考温度”界面。
参考温度
本仪器是用参考温度来计算具有温度补偿的电导率值的，此参考温度默认值为25℃。你可以用上键和下键调节这个参考温度值，调整范围是15~ 25℃，按“ENTER” 键储存新的设定值，或者按“MODE”键退出储存，进入“电导率校正”界面。
电导率校正
(a) 将电导率电极清洗后，放入已知电导度的标准溶液中，此标准溶液的选择更好基于被测溶液电导值的范围之内。把电极浸入标准溶液中（至少2~3英寸或者5~7cm），并稍作搅动以便消除电极极片上的空气泡。
(b) 稍等片刻，等待温度稳定。在此期间，主机显示“rAGE” 表示主机在自动抓取测量的量程，这是正常的。当温度稳定后，你可以用上键和下键调节这个标准的电导度值（25℃），按“ENTER”键确认。当主机发出哔哔声后，表示校正步骤已成功完成，主机自动退到测量模式。
C. 电导率的测量
1. 电极接上仪表后，开机，把清洗后的电极直接放入被测溶液中（至少浸没2~3英寸或者5~7cm)，稍做搅动，赶出电极极片上的空气泡。
2. 按“MODE” 键切换到自己需要测量的参数。机器在自动切换量程的时候显示“rAGE”这是正常的。当温度稳定后，就可以读取测量值，此值为被测溶液的测量值。
D. 存储、回叫和清除数据
a. 存储数据。
1. 在带温度补偿的电导率、盐度、总固体溶解量及无温度补偿的电导率模式，按“CLEAR/ENTER”键一次，机器将存储当前数据值。此时“Save”显示将显示一次，并且有一位置号也同时显示，表示当前界面值已被存储并做了此位置号的记录。
2. 如果界面上显示“Full”，则代表机器的50组数据已存储满了，不能再存储其他数据。使用者只能删除或删除部分数据才能存储新的数据。
b. 回叫存储数据。
1. 按“MODE”键进入回叫模式，按“CLEAR/ENTER”键，机器将显示最后一组存储数据。
2. 此时按上键或下键选择位置号，找到自己需要读取的存储数据。.
3. 读取完存储数据后可按“MODE”键退出回叫模式。
c. 清除存储数据。
1. 按“MODE”键进入清除模式，按“CLEAR/ENTER”键，机器将进入清除方式的选择，可按上键或下键在“Delete All”和“Delete Each”之间选择。
2. 在“Delete All”界面，按此键一次，机器将删除所有存储的数据，并显示None，表示没有存储数据。
3. On the “Delete Each” interface, press this key once, and the machine will enter the interface for deleting a single stored data. At this time, you can press the up and down keys to select the position number to be deleted, press this key to confirm, and the machine will delete The stored data of this position number, at the same time, the stored data of this position number will be replaced by the stored data of the next position number.
For example: 01,400uS,25℃;
02,5mS,23.8℃;
03,18mS,15.6℃;
…
If the stored data of 02 position number is cleared, the stored data of the machine becomes:
01,400uS,25℃;
02,18mS,15.6℃;
…
4. After clearing the data, press the "MODE" key to exit the clearing mode.
