1. Introduction
The GIDIGI 4-in-1 Digital Tester is a versatile instrument designed for accurate measurement of pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), and temperature in various water solutions. This device is suitable for applications such as hydroponics, aquariums, drinking water analysis, swimming pools, and brewing. Its multi-functional capabilities provide essential data for monitoring and maintaining optimal water quality.
Image 1.1: The GIDIGI 4-in-1 Digital Tester shown with its included pH calibration solutions.
2. Product Features
- Multi-functional 4-in-1 Measurement: Measures pH, TDS, EC, and temperature.
- Wide Test Range: pH (0.1-14.0), EC (0-9990µS/cm, 10.01-19.99mS/cm), TDS (0-9990ppm), and temperature (32.0-140.0℉, 0.0-60.0℃).
- Simultaneous Display: Shows pH, TDS/EC, and temperature readings concurrently on the screen.
- Automatic Temperature Compensation (ATC): Ensures accurate readings across a temperature range of 0 to 50°C (32 to 122°F).
- High Sensitivity Probe: Features a resolution of 0.1 pH for precise measurements.
- Green Backlight Display: Provides clear readings in various lighting conditions.
- Memory Function: Retains the last used display mode upon startup.
- Replaceable Electrodes: Designed for extended product life.
Image 2.1: The tester's display showing simultaneous readings for pH, TDS/EC, and temperature.
3. Package Contents
Upon unpacking, please verify that all items are present:
- GIDIGI 4-in-1 Digital Tester (Model: GX-pST04B) x 1
- Instruction Manual x 1
- pH Calibration Solution (4.00 pH) x 1
- pH Calibration Solution (7.00 pH) x 1
- pH Calibration Solution (10.01 pH) x 1
4. Product Overview
The GIDIGI tester features a robust design with an easy-to-read digital display and intuitive controls. The sensitive probe is protected by a cap to maintain its condition.
4.1. Components
- Display Screen: Shows pH, TDS/EC, and temperature readings.
- Power Button (①): Turns the device on/off.
- TEMP Button: Switches temperature units (℃/℉) and initiates pH calibration.
- MODE Button: Switches between TDS and EC readings and initiates EC calibration.
- Probe: The sensing element for water quality measurements.
- Protective Cap: Covers the probe when not in use to keep it moist.
Image 4.1: Detailed view of the high-sensitivity probe and internal electrode stabilization chip.
5. Setup
5.1. Battery Installation
The device typically comes with batteries pre-installed (4 x LR44). If replacement is needed, open the battery compartment at the top of the device and insert new batteries, ensuring correct polarity.
5.2. Initial Preparation
- Remove the protective cap from the probe.
- Rinse the probe with distilled water before first use and after each measurement.
- Gently shake off excess water. Do not wipe the probe, as this can damage the sensitive glass bulb.
6. Operating Instructions
6.1. Power On/Off
- To turn on: Press the Power button (①).
- To turn off: Press and hold the Power button (①) for approximately 5 seconds until the display turns off.
6.2. Taking Measurements
- Ensure the tester is clean and calibrated (refer to Section 7).
- Immerse the probe into the sample solution, ensuring the liquid level is below the plastic casing.
- Gently stir the solution and wait for the readings to stabilize on the display.
- Record the pH, TDS/EC, and temperature values as needed.
- After measurement, rinse the probe with distilled water and replace the protective cap.
6.3. Switching Modes and Units
- Temperature Unit (℃/℉): Press the TEMP button to toggle between Celsius and Fahrenheit.
- TDS/EC Mode: Press the MODE button to switch between TDS (ppm) and EC (µS/cm or mS/cm) readings.
Image 6.1: The tester in use for measuring drinking water quality.
Image 6.2: The tester being used to monitor nutrient solution in a hydroponic setup.
Image 6.3: The tester providing direct pH, PPM, and temperature values for pool water.
7. Calibration
Regular calibration ensures the accuracy of your GIDIGI tester. It is recommended to calibrate pH weekly and EC monthly, or more frequently if precise measurements are critical.
7.1. pH Calibration
The tester supports 3-point pH calibration (4.00, 7.00, 10.01 pH). Always calibrate 7.00 pH first.
- Prepare the 7.00 pH buffer solution.
- Turn on the tester and immerse the electrode into the 7.00 pH solution.
- Press and hold the TEMP button (labeled 'pH CAL') for 5 seconds. The display will show 'CAL' and the 7.00 pH value will flash 3 times, indicating successful calibration.
- Rinse the electrode with distilled water.
- Repeat the process for 4.00 pH and 10.01 pH solutions, calibrating them after the 7.00 pH point.
Image 7.1: Visual guide for pH calibration using buffer solutions.
7.2. EC Calibration
The tester is typically factory-calibrated for EC. If recalibration is needed, use a 1413 µS/cm (or 12.88 mS/cm or 5000 µS/cm) standard solution.
- Prepare the 1413 µS/cm EC calibration solution.
- Turn on the tester and immerse the electrode into the EC solution. Wait for the value to stabilize.
- Press and hold the MODE button (labeled 'EC CAL') for 5 seconds. A flashing value will appear on the screen.
- Use the up/down arrows (often integrated with TEMP/MODE buttons, refer to specific device markings) to adjust the displayed value to match 1413.
- The value will flash three times, indicating calibration is complete.
- Rinse the electrode with distilled water and dry it.
Image 7.2: Visual guide for EC calibration using a standard solution.
8. Maintenance
8.1. Cleaning the Electrode
- Always rinse the electrode with distilled or deionized water before and after each use.
- For stubborn residue, gently clean the EC electrode probe with a cotton swab.
- Do not use abrasive materials or harsh chemicals.
8.2. Probe Storage
- Keep the electrode moist by regularly adding electrode protection liquid (KCL solution) to the protective cap.
- If KCL solution is unavailable, add three drops of water to the cap to prevent the probe from drying out.
- Ensure the protective cap is securely replaced when the tester is not in use.
8.3. Battery Replacement
When the battery indicator on the display shows low power, replace the LR44 batteries as described in Section 5.1.
9. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Inaccurate readings | Uncalibrated sensor, dirty probe, dried-out probe. | Calibrate the tester (Section 7). Clean the probe (Section 8.1). Re-moisten the probe (Section 8.2). |
| Display not turning on | Dead batteries, incorrect battery installation. | Replace batteries (Section 5.1). Check battery polarity. |
| Slow response time | Dirty probe, aged probe. | Clean the probe (Section 8.1). Consider replacing the electrode if cleaning does not improve performance. |
| Readings fluctuate excessively | Air bubbles on probe, unstable sample temperature, electrical interference. | Gently stir the solution to remove bubbles. Allow sample to reach stable temperature. Ensure no strong electrical fields nearby. |
10. Specifications
| Parameter | Range | Resolution | Accuracy |
|---|---|---|---|
| pH | 0.00 - 14.00 pH | 0.01 pH | ±0.05 pH |
| TDS | 0 - 9990 ppm | 1 ppm | ±2% F.S. |
| EC | 0 - 9990 µS/cm 10.01 - 19.99 mS/cm | 1 µS/cm 0.01 mS/cm | ±2% F.S. |
| Temperature | 0.0 - 60.0 ℃ 32.0 - 140.0 ℉ | 0.1 ℃/℉ | ±0.5 ℃ |
- Automatic Temperature Compensation (ATC): 0 - 50 ℃ (32 - 122 ℉)
- Automatic Shutdown: 5 minutes
- Power Supply: 4 x 1.5V LR44 button cell batteries
- Dimensions: Approximately 10 x 5.75 x 2.25 inches
- Weight: Approximately 1.05 Pounds
11. Warranty and Support
GIDIGI products are manufactured to high-quality standards. For specific warranty information or technical support, please refer to the product packaging or contact GIDIGI customer service through the retailer where the product was purchased. Keep your purchase receipt for warranty claims.
