EUTECH INSTRUMENTS TDS 6 (01) PDF Document

The large custom LCD on the EUTECH INSTRUMENTS TDS 6 has 4-digit segments and various operation annunciators:

1. **Primary display:** Shows the main reading.

2. **ppm/ppt:** “Parts Per Million” or “Parts Per Thousand” indicator for TDS measurement.

3. **°C:** Temperature indicator.

4. **%:** Percentage indicator for the Temperature Coefficient.

5. **LO:** Low battery indicator.

6. **HO:** Hold (frozen) reading indicator.

The EUTECH INSTRUMENTS TDS 6 has a 6-key splash-proof keypad with the following functions:

• **ON/OFF:** Powers on and shuts off the meter. It takes you directly into measurement mode when switched on.

• **CAL:** Enters calibration mode for TDS and Temperature. It can also be used to abort calibration or setup mode without confirming any set value.

• **HOLD/ENTER:**

– **HOLD:** Freezes the measured reading in measurement mode. Press again to release.

– **ENTER:** Confirms values in calibration mode and confirms selections in SETUP mode.

• **▲ (Up Arrow):**

– In Calibration Mode: Scrolls through calibration values.

– In Setup Mode: Scrolls through the setup sub-group programs.

– In Measurement Mode: Activates the manual ranging function. Each press moves to a higher TDS range.

• **▼ (Down Arrow):**

– In Calibration Mode: Scrolls through calibration values.

– In Setup Mode: Scrolls through the setup sub-group programs.

• **MODE:**

– Selects the measurement mode for TDS and Temperature.

– When pressed together with the ON/OFF key, it enters the SETUP mode to customize meter preferences.

The battery compartment is located at the back of the EUTECH INSTRUMENTS TDS 6. Follow these steps to insert the batteries:

1. Push the cover in the direction of the arrow and lift it up.

2. Note the polarity of the battery and insert four “AAA” batteries into their position.

3. After replacement, place the cover back and press down until it locks tight.

When the “LO” annunciator appears on the LCD, it alerts you that the battery power is running low. Power off the meter before changing the batteries.

To connect the conductivity/TDS electrode to your EUTECH INSTRUMENTS TDS 6, follow these steps:

1. To connect the BNC connector, align the connector slots with the posts of the meter’s socket and rotate the connector clockwise until it locks.

2. To remove the BNC connector, rotate it in an anti-clockwise direction until it unlocks, and slide the connector off the socket.

3. Insert the mini phono jack of the temperature sensor into its corresponding socket on the meter.

4. Unplug the phono jack when you want to measure TDS without temperature compensation (Manual Temperature Compensation).

CAUTION: Do not pull or force the probe cord, as the wires might disconnect. Keep connectors clean and do not touch them with soiled hands.

When you press the ON/OFF key to power up your EUTECH INSTRUMENTS TDS 6, it will go through a series of displays showing the setup parameters:

1. The first screen shows [tdS 6], which is the meter’s name.

2. The second screen shows [C 1.0], the conductivity cell constant (k). The default is k=1.0.

3. The third screen shows [t 25.0 °C], the Normalization Temperature. The default is 25 °C.

4. The fourth screen shows the TDS factor (e.g., [t 0.50]). The default is 0.5.

5. The next screen shows [t 2.1%], the Temperature Coefficient. The default is 2.1 %/°C.

6. All LCD segments will light up for 2 seconds.

7. The meter then enters the measurement mode and is ready for use.

To switch between the TDS measurement mode and the Temperature measurement mode on your EUTECH INSTRUMENTS TDS 6, simply press the MODE key. A customized annunciator on the display will indicate which measurement parameter you are currently viewing (°C for temperature, or ppm/ppt for TDS).

The EUTECH INSTRUMENTS TDS 6 has five measuring ranges, and you can calibrate one point in each range. You should use a calibration solution that falls within the “recommended calibration solution range” for the range you are measuring.

When you recalibrate, the new calibration data replaces the old data for that specific range only. To completely recalibrate your meter, it is best to first restore factory default values.

In Manual Calibration mode, you can use customized TDS calibration standards. The procedure is as follows:

1. If necessary, press the MODE key to select the TDS measurement mode.

2. Rinse the probe thoroughly with de-ionized water or a rinse solution, then rinse with a small amount of your calibration standard.

3. Dip the probe into the calibration standard. Immerse the probe tip beyond the upper steel band. Stir the probe gently and allow time for the reading to stabilize.

4. Press the CAL key to enter calibration mode. The [CA] indicator will appear for 1.5 seconds, and a value will begin flashing.

5. Wait for the value to stabilize, then press the ▲ or ▼ key to adjust the displayed value to match the value of the calibration standard you are using.

6. Press the ENTER key to confirm. The [CO] indicator will appear for 1.5 seconds, and the meter will return to measurement mode.

7. To perform multi-point calibration for other ranges, repeat steps 1-6 with the appropriate standard for each range.

The temperature sensor is factory calibrated, but you can recalibrate it if you suspect errors. You can offset the reading up to ±5 °C from the default reading.

1. Make sure the temperature sensor’s phono jack is properly connected to the meter.

2. Switch on the meter and press the MODE key to select the temperature measurement mode.

3. Press the CAL key to start the temperature calibration process.

4. Dip the probe into a solution with a known temperature (e.g., a temperature bath). Allow time for the temperature to stabilize.

5. Wait for the value to stabilize, then press the ▲ or ▼ key to adjust the displayed value to match the solution’s known temperature.

6. Press the ENTER key. The [CO] indicator will appear for 1.5 seconds, and the reading will stop flashing. The meter then returns to measurement mode.

To exit calibration without confirming, press the CAL key again.

To take readings with your EUTECH INSTRUMENTS TDS 6:

1. Rinse the probe with de-ionized or distilled water before use. To avoid sample contamination, rinse the probe with a small amount of your sample liquid.

2. Press the ON key to switch on the meter.

3. Dip the probe into the sample. Ensure the liquid level is above the upper steel band on the probe. Stir the probe gently to create a homogenous sample.

4. Allow time for the reading to stabilize, then note the reading on the display.

For measurements with Automatic Temperature Compensation (ATC), ensure the temperature sensor phono jack is securely inserted. For Manual Temperature Compensation, unplug the phono jack and manually set the temperature value.

By default, your EUTECH INSTRUMENTS TDS 6 has an auto-ranging function. However, you can manually select a specific range by pressing the ▲ key successively. The five ranges are:

If the value of the solution you are measuring is higher than the selected range, [Or] will appear on the display. Press the ▲ key until the correct range is selected. The meter resets to the Auto-ranging function once it is turned off.

The HOLD function allows you to freeze the display for delayed observation.

1. To hold a measurement, press the HOLD key while in measurement mode. The [HO] annunciator will appear on the display.

2. To release the held value and continue taking measurements, press the HOLD key again.

Note that the meter shuts off automatically after 20 minutes of nonuse. If the meter is shut off, either automatically or manually, the HOLD value will be lost.

The advanced setup mode lets you customize the meter’s preferences and defaults.

1. Make sure the meter is switched off.

2. Press and hold the ON and MODE keys simultaneously for 2 seconds. Release the ON key first, then release the MODE key.

3. The [StUP] indicator will appear momentarily, followed by the first menu item.

4. Use the ▲ or ▼ keys to scroll through the different setup menu options.

5. Press ENTER to select a menu option and change its settings.

6. Press CAL to exit the setup menu at any time and return to measurement mode.

The following settings can be customized in the Advanced Setup menu:

The TDS conversion factor is used by the meter to convert from conductivity to TDS. You can set this factor between 0.4 and 1.0 (default is 0.5).

1. Enter the advanced setup mode as described previously.

2. Press the ▲ or ▼ key until [tdS] appears on the LCD. Press the ENTER key.

3. Press the ▲ or ▼ key to select your desired value between 0.4 and 1.0.

4. Press the ENTER key to confirm your selection. The meter will take you back to the menu, displaying [tdS].

5. Press the ▲ or ▼ key to move to the next menu or press CAL to exit to measurement mode.

This function resets all parameters, including calibration data, to factory default settings. This action is not reversible.

1. Enter the advanced setup mode.

2. Press the ▲ or ▼ key until [UrSt] appears on the LCD. Press the ENTER key.

3. Press the ▲ or ▼ key to select [Yes].

4. Press the ENTER key to confirm.

5. The meter will go back to measurement mode after completing the switch-on initialization sequence.

Proper probe care is essential for accurate readings:

• Keep the conductivity probe clean. Rinse it twice and gently swirl it while taking readings.

• For best accuracy, soak a dry probe for at least 5 to 10 minutes before calibration.

• Always rinse the probe with deionized or tap water before storing.

• Never scratch the sensor bands with a hard substance or strike the probe against any hard surface.

• Do not immerse the probe in oily solutions. To clean, stir it in a mild detergent bath or isopropyl alcohol, wipe with a soft tissue, rinse thoroughly, and then recalibrate the meter.

The probe guard is removable for easy cleaning:

1. Grip the yellow probe guard and twist it clockwise. The locking notch will release.

2. Slide the probe guard off the end of the probe.

Remember to re-attach the probe guard before taking readings to avoid errors.

If you are experiencing unstable readings, check for the following causes and solutions:

• **Air bubbles in probe:** Tap the probe to remove bubbles.

• **Dirty probe:** Clean the probe as per the maintenance instructions and re-calibrate.

• **Probe not deep enough in sample:** Make sure the sample entirely covers the probe sensors (past the upper steel band).

• **External noise/induction:** Move the meter away from or switch off any nearby interfering electric motors.

• **Broken probe:** If the problem persists, you may need to replace the probe.

If an error message appears, switching the meter off and on again may eliminate it. If the error persists or the meter shows incorrect values, the unit may need service.

• You only need one calibration for measurement throughout the entire range of the meter. The meter automatically uses the closest range’s calibration data if a specific range was not calibrated. However, only calibrated ranges have maximum accuracy.

• If measuring in ranges near to or greater than 10 ppt, or near to or lower than 50 ppm, calibrate the meter at least once a week for specified ±1% F.S. accuracy.

• If measuring in mid-ranges and you store the probe dry after washing in deionized water, calibrate the meter at least once a month.

• Wet the probe for 10 minutes before calibrating or taking readings to saturate the probe surface and minimize drift.

• If you make measurements at extreme temperatures, calibrate the meter at least once a week.

To determine the conductivity-to-TDS conversion factor for a specific solution, use the following formula:

Factor = Actual TDS ÷ Actual Conductivity @ 25 °C

Definitions:

• **Actual TDS:** The value from the solution bottle label or a standard you prepare using high purity water and precisely weighed salts.

• **Actual Conductivity:** The value measured using a properly calibrated Conductivity/Temperature meter.

Both the Actual TDS and the Actual Conductivity values must be in the same magnitude of units. For example, if the TDS value is in ppm, the conductivity value must be in µS. If the TDS value is in ppt, the conductivity value must be in mS.

To determine the temperature coefficient (tc) of your sample solution, follow this procedure:

1. Immerse the probe into a sample of your solution. In the Advanced Setup menu, adjust the temperature coefficient to 0.0% (no compensation).

2. Wait for 5 minutes. Note the temperature T₁ and the conductivity C_T1.

3. Condition the sample solution and probe to a new temperature (T₂) that is about 5 °C to 10 °C different from T₁. Note the new conductivity reading C_T2. Ideally, T₁ and T₂ should bracket your normal measurement temperature and not differ by more than 5 °C.

4. Calculate the temperature coefficient using the following formula:

tc = 100 x [ (C_T2 – C_T1) / (C_T1(T₂ – 25) – C_T2(T₁ – 25)) ]

5. Enter the calculated temperature coefficient value into the meter via the Advanced Setup menu ([t.Co %]).