GAOTek Conductivity Meter with TDS (10 Optional Parameters) is designed as 5-points calibration meter, and selectable TDS conversion factor with an accuracy of 0.5% F.S. The Reset feature automatically resumes all parameters back to factory default settings. The expanded memory stores and recalls up to 500 readings. Built-in real-time clock stamps stores data to meet GLP standard. Stored data can be transferred into computer by USB communication interface. Multi-mode power scheme (battery, power adapter, computer’s USB port) ensures that the meter runs smoothly.
- The Conductivity Meter with TDS (10 Optional Parameters) is equipped with a large backlit LCD display.
- 1 to 5 points push-button calibration with automatic calibration solution recognition.
- Selectable cell constant (0.1/1/10), TDS conversion factor, normalization temperature, linear and pure water compensation modes.
- Automatic Temperature Compensation provides accurate reading over the entire range.
- Calibration Due Reminder prompts user to calibrate the meter regularly.
- Stability indicator automatically shows current measurement status.
- Auto-Hold function freezes stable measured value for easy viewing and recording.
- Selectable temperature unit (°C or °F) meets different application requirements.
- Automatic electrode diagnosis shows cell constant of the conductivity electrode.
- System menu allows setting the 10 parameters, including the number of calibration points, stability condition, and temperature unit, hold function, etc.
- Built-in real-time clock stamps stored data to meet GLP standard
- Help message as an operational guide that helps you quickly begin using the meter.
- Multi-mode power scheme (battery, power adapter, computer’s USB port) ensures that use the meter smoothly.
|Measuring Range||0~20.00, 200.0, 2000 µS/cm, 20.00, 200.0 mS/cm|
|Accuracy||± 0.5 % F.S|
|Calibration Points||1 to 5 Points|
|Calibration Solutions||10 µS/cm, 84 µS/cm, 1413 µS/cm, 12.88 mS/cm, 111.8 mS/cm|
|Temperature Compensation||32 °F ~ 212 °F (0 °C ~ 100 °C)|
|Temperature Coefficient||0.0 ~ 10.0%/°C|
|Compensation Modes||Linear or Pure Water|
|Cell Constant||K=0.1, 1, 10|
|Normalization Temperature||20 °C or 25 °C|
|Range||0 ~ 100 ppt (Max. 200ppt, depending on factor setting)|
|Accuracy||± 1 % F. S|
|TDS Factor||0.1 ~ 1.0 (Default 0.5)|
|Range||32 °F ~ 221 °F (0 °C ~ 105 °C)|
|Accuracy||± 0.9 °F (± 0.5 °C)|
|Resolution||32.8 °F (0.1 °C)|
|Calibration Points||1 Point|
|Calibration Range||Measured value ± 50 °F (± 10 °C)|
|Hold Function||Manual or Automatic|
|Stability Conditions||Low or High|
|Calibration Due||0 to 31 Days|
|Power Off||Manual or Automatic (10, 20, 30 minutes)|
|Memory||Stores up to 500 data sets|
|Output||USB Communication Interface|
|Connector||6-pin Mini Plug|
|Power Requirements||3 × 1.5 V “AA” Batteries|
|Battery Life||Approximately 150 Hours (Turn Off the Backlit)|
|Dimensions||6.69 in × 3.34 in × 1.18 in
(170 mm × 85 mm × 30 mm) (L x W x H)
|Weight||10.58 oz. (300 g)|
- Water quality monitoring
- Geological and ecological research
- Cooling towers
- Printing industry
- Swimming pools and Spas
- Agriculture and aquaculture
- Education and lab applications
- Conductivity Electrode
- Temperature Probe
- Conductivity Calibration Solutions (84µS/cm, 1413µS/cm, 12.88mS/cm)
- AA Batteries Conductivity Electrode Temperature Probe Conductivity Calibration Solutions
The Conductivity Meter with TDS (10 Optional Parameters) is equipped with a clear and bright LCD display that used to show measured values, mode indicators and help message. The following table describes the meaning of each indicator.
|Measurement mode indicator: Indicates meter is in the measurement mode|
|Low Battery Alarm: When battery is depleted, the indicator will disappear|
|Calibration mode indicator: Indicates meter is in the calibration mode|
|Stable indicator: Indicates the measured value has stabilized|
|Setup mode indicator: Indicates meter is in SETUP mode|
|Hold indicator: Indicates the displayed value has been frozen|
|Memory mode indicator: Indicates data is stored into memory|
|Calibration Due Reminder: Prompts user to calibrate the meter regularly|
The meter has a succinct membrane keypad, names and symbols describe each function key controls.
|● Power the meter ON/OFF.
● Freezes the measured value on the display, press the key again to resume measuring.
● In the calibration or setting mode, exits current mode and returns to measurement.
|● Toggles between available measurement modes (Conductivity, TDS).
● Press and hold the key to enter temperature setting mode.
|● Press the key to enter the calibration mode.
● Press and hold the key to enter the setup menu.
|● Press the key to store current measured value.
● Press▲ key in setup mode to scroll up through menu.
● Press▲ key in temperature setting mode to increase the setting value.
|● Press the key to view calibration report or stored data.
● Press ▲key in setup mode to scroll down through menu.
● Press ▲ key in temperature setting mode to decrease the setting value
|● Confirms the calibration, setting value or displayed option.
● Press and hold the key to turn On/Off the backlight.
Connecting the Conductivity Electrode:
Take out the conductivity electrode from the carrying case. Insert the 6-pin connector into corresponding connector socket. Ensure the connector is fully seated. After connection is completed, DO NOT pull on the sensor cord. Always make sure that the connector is clean and dry.
Prior to Use:
Soak the conductivity electrode for a few minutes in tap water to remove dirt and oil stains on the electrode.
- Press MEAS key to turn on the meter, the display shows measured values, mode indicators and help messages.
- Press and hold the MEAS key for 3 seconds, the meter will turn off.
- If you do not press any key within the specified period, the meter will turn off automatically.
To disable the auto-off function, please read the SETUP MENU section.
GAOTek Conductivity Meter with TDS (10 Optional Parameters) contains an integrated setup menu that allows you to customize each displayed option to meet measurement requirements
|Cell Constant: Select the cell constant of conductivity electrode.||0.1||K=0.1|
|Calibration Points: Select the number of calibration points.||1||1 point||●|
|Temperature Coefficient: Select the temperature coefficient of sample||2.10||Setting Range: 0.0 to 10.0%/°C||2.10|
|Pure Water Coefficient: Pure water coefficient will be calculated and applied automatically for ultra-pure water measurement if enabled.||Enable|
|Normalization Temperature: Sets the normalization temperature for conductivity measurement and calibration.||25 °C||25 °C||●|
|20 °C||20 °C|
|TDS Factor: Sets the default TDS conversion factor||0.5||Setting Range: 0.40 to 1.00||0.5|
|Measurement Unit: Sets the default temperature unit.
|Stability Criteria: Sets the stability criteria for measurement. When the “LO” option is enabled, measuring value will stabilize quickly, but reading is less accurate. When the “HI” option is enabled, measuring value will stabilize slowly, but guarantees high accuracy.||Low||●|
|Auto-Hold: When the auto-hold function is enabled, the meter will automatically sense a stable end-point reading and freeze it.||Enable|
|Auto-Power Off: When the auto-off power is enabled, if you do not press any key within a specified time period, the meter will automatically turn off.||10||10 minutes|
|Calibration Due: When calibration due reminder is enabled, if you do not recalibrate meter within a specified time period, the meter will automatically show indicator.||1 to 31 days|
|Date and Time: Sets the date and time of the meter.||—||—|
|Clear stored data: Clear all stored data.||Enable|
|Reset: Reset function allows user to restore the meter back to factory default parameters. When this function is enabled, all calibration values and selected parameters will be lost or reset.||Enable|
In order to get accurate measuring results, you need to enable the manual or automatic temperature compensation before measurement or calibration.
Automatic Temperature Compensation:
- Insert the connector of temperature probe into the meter’s phone jack.
- The “ATC” indicator will show on the display; the meter is now switched to automatic temperature compensation mode.
Manual Temperature Compensation:
- DO NOT connect the temperature probe to meter.
- Press and hold the °C key for 3 seconds to enter temperature setting mode.
- Press ▼ or ▲ key to set the temperature value of sample.
- Press ENTER key to confirm, the meter returns to measurement mode. Setting is completed.
GAOTek Conductivity meter with TDS (10 Optional Parameters) can use three types of conductivity electrodes. Before calibration or measurement, you need to select the different sensors as per your sample concentration. The table below shows available sensors and its effective measuring ranges.
|CONDUCTIVITY ELECTRODE||MEASURING RANGES||CELL CONSTANT|
Make sure that you selected the cell constant between 0.1, 1 or 10 in the setup menu. If the current option is “USER”, the automatic calibration function will be disabled (Refer to Setup Menu section).
In the automatic calibration mode, the meter allows up to 5 points calibrations. To ensure higher accuracy, we recommend that you perform 3 points calibrations or select a standard value close to the sample value you are measuring. The meter will automatically detect these conductivity standard solutions and prompt the user to calibrate the meter. When the calibration is completed, all new calibration values will automatically override existing data.
The following table shows acceptable conductivity range of calibration solution for each measuring range.
|MEASURING RANGES||CALIBRATION SOLUTION RANGE||DEFAULT|
|0~20 µS/cm||7~17 µS/cm||10 µS/cm|
|20~200 µS/cm||70~170 µS/cm||84 µS/cm|
|200~2000 µS/cm||700~1700 µS/cm||1413 µS/cm|
|2~20 mS/cm||7~17 mS/cm||12.88 mS/cm|
|20~200 mS/cm||70~170 mS/cm||111.8 mS/cm|
Single Point Calibration:
- Press MODE key until the meter shows indicator.
- Rinse the conductivity electrode with distilled water, then rinse with a small amount of calibration solution.
- Press CAL key, the meter enters the calibration mode.
- Dip the conductivity electrode into the calibration solution, the meter automatically shows current calibration standard (e.g., 1413µS/cm).
- Press ENTER key to confirm, “Calibration” indicator begins flashing
- Wait for the measured value to stabilize, the display shows “END”. The meter returns to measurement mode automatically. Calibration is completed.
- Make sure that you have selected 2 to 5 points calibrations in setup menu.
- Repeat steps 1 to 2 above, when the first calibration point is completed, the display will show “CAL2”. The meter prompts you to continue with second point calibration.
- Rinse the conductivity electrode with distilled water. Dip the electrode into the next calibration solution, the meter automatically shows current calibration standard (e.g., 12.88mS/cm).
- Press ENTER key to confirm, “Calibration” indicator begins flashing.
- Wait for the measured value to stabilize, the display shows “CAL3”. The meter prompts you to continue with third point calibration.
- Repeat steps 3 to 4 above until the display shows “END”. The meter returns to measurement mode automatically. Calibration is completed.
GAOTek Conductivity meter with TDS (10 Optional Parameters) provides a quick manual calibration mode that allows user to easily calibrate the meter.
- Record the cell constant value on the electrode (e.g., K=1.08).
- Press and hold the key for 3 seconds to enter setup menu, the display shows “CELL” option
- Press ENTER key to confirm, the meter enters the cell constant setting mode.
- Press ▼ or ▲ key to select “USER” option.
- Press ENTER key to confirm, the meter enters User-Defined mode.
- Press ▼ or ▲ key to set each digit according to previous record.
- Press ENTER key to confirm until the setting values stop flashing. The meter returns to measurement mode automatically. Setting is completed.
Conductivity Calibration Report:
This program lets you check the calibration factor of the conductivity electrode.
- Press MR Key in the conductivity measurement mode, the display shows “LOC/P-01”.
- Press ▼ or ▲ key until the meter shows “ELE/P-02” (Electrode Diagnosis).
- Press ENTER key to confirm, the meter shows the last calibration date (Format: mm-dd).
- Press ▼ key, the meter shows calibration point and calibration factor (e.g., K=0.998).
- After the browsing, press MEAS key to exit the current mode.
During the measurement, when automatic temperature compensation is enabled, if the temperature reading displayed differs from that of an accurate thermometer, you need to calibrate the meter.
- Press and hold the °C key for 3 seconds to enter temperature calibration mode, the display shows current temperature reading.
- Press ▼ or ▲ key to set the temperature value.
- Press ENTER key to confirm. Calibration is completed.
Switching the Measurement Mode:
- In the conductivity mode, press MODE key until the display shows indicator. The meter now enters to TDS measurement mode.
- Press MODE key again, the meter returns to conductivity mode.
- Rinse the conductivity electrode thoroughly with distilled water.
- Dip the electrode into the sample solution, stir the sensor gently.
- Wait for the reading to stabilize, record the measured value on the display.
The meter contains two data hold modes. When the Auto-Hold function is enabled, the meter will automatically sense a stable endpoint reading and freeze it, “HOLD” indicator appears on the display. If the Auto-Hold function is disabled, press key, the meter will immediately freeze currently displayed value. Press the key again to resume measuring.
Storing and Recalling Data from Memory
GAOTek Conductivity meter with TDS (10 Optional Parameters) allows up to 500 data sets to be stored and recalled.
GAOTek Conductivity meter with TDS (10 Optional Parameters) provides a free Data Acquisition System that can be used to transfer data, receive the measuring values or import the data to Excel. Before using, ensure that Windows 7/8/10 operating system has been installed on your computer.
- Connect the USB cable to meter and computer. Click the DAS icon, the system will automatically scan an available communication port and show the message box “Found a port on your computer”.
- Click the OK button, the application starts.
- Click the Connect button, the screen shows “Port is connected” indicate that communication between the meter and the computer has been established.
- Click the OK button to confirm.
- Click the Receive button, the stored data in meter will automatically send to computer.
This function helps you to record the measuring value within the specify time.
- Click the Interval Recording button and select a time option.
- Click the Receive button, the measured value will automatically send to data sheet.
This function helps you to view variations of the measured parameter continuously. Click the Graph button, the screen will immediately show curve graph. If you want to quit current mode, click the Back button.
Create the Excel File:
When the transfer is completed, click the “Save as Excel” button, the measured values in the data sheet will automatically convert to Excel file.
Once the software is closed, all received data will be lost and cannot be recovered.
|LCD DISPLAY||CAUSE||CORRECTIVE ACTION|
|——||Electrode dried out||Soak the conductivity electrode in tap water for 10 minutes|
|Measured value is out of range||Check the electrode whether dirty or broken|
|Electrode does not suit the current sample||Replace the conductivity electrode|
|Err||Setting value does not match calibration solution||Reset the calibration value|
|Electrode is broken||Replace the conductivity electrode|
|Keypad is not working properly||Replace the batteries|
Conductivity Electrode Care and Maintenance:
- Ensure that the conductivity electrode is thoroughly washed with distilled water after each use.
- If there is a build-up of solids inside the measurement area of the cell, these should be removed very carefully with a cotton bud soaked in solvent, taking care not to touch the metal parts of the inner cell.
How to prepare the conductivity standard solutions
Place AR potassium chloride reagent in a 50 mL beaker and dry in an oven for 3 to 5 hours at 221 °F (105 °C), then cool to room temperature in desiccator.
|84 µS/cm||Accurately weigh out 42.35 mg of KCL and dissolve in 1000 mL de-ionised water|
|1413 µS/cm||Accurately weigh out 745.9 mg of KCL and dissolve in 1000 mL de-ionised water|
|12.88 mS/cm||Accurately weigh out 7.45 g of KCL and dissolve in 1000 mL de-ionised water|
|111.8 mS/cm||Accurately weigh out 74.5 g of KC, and dissolve in 1000 mL de-ionised water|
Stir the solution until the reagent has thoroughly mixed. Preparation is completed.
How to calculate the temperature coefficient
To determine the temperature coefficient of sample solution use this formula:
- Press and hold the °C key for 3 seconds to enter temperature setting mode.
- Press or key to set the temperature at 77 °F (25 °C).
- Dip the electrode into sample solution A.
- Record the temperature value TA and conductivity value CTA.
- Repeat the steps above, dip the electrode into same sample solution B. Make sure both sample solutions have about 41 °F (5 °C) to 50 °F (10 °C) difference.
- Record the temperature value TB and conductivity value CTB.
- Calculate the temperature coefficient of sample solution according to the formula shown above.
- Enter the calculated temperature coefficient into the meter.
How to calculate the TDS conversion factor
To determine the TDS conversion factor use the following formula:
Actual TDS: value from the high purity water and precisely weighed NaCl or KCL reagent.
Actual Conductivity: the meter measured conductivity value .
How to calculate the TDS conversion factor?
To determine the TDS conversion factor use the following formula:
For example: Dissolve 64 g of potassium chloride reagent in 1L distilled water. If its conductivity value is 100mS/cm, then TDS conversion factor is 0.64.