Manuals+

CEM DT-8321

CEM DT-8321 Portable Dew-Point Hygrometer

Instruction Manual

1. Introduction

The CEM DT-8321 is a professional hand-held dew-point, temperature, and humidity meter designed for industrial field testing and calibration. It accurately measures dew point temperature over a wide range, and its probe can be inserted directly into pressurized processes. The sensor is robust, capable of withstanding condensation, and recovers fully from wet conditions, making it suitable for direct process dew point measurement across various temperature and pressure ranges.

CEM DT-8321 Dew-Point Hygrometer held in hands, showing the main unit and the probe.
Figure 1: CEM DT-8321 Dew-Point Hygrometer main unit and probe.

The image shows the CEM DT-8321 main unit held in one hand, displaying temperature, dew point, and relative humidity on its color screen. The detachable probe is held in the other hand, connected to the main unit via a cable.

2. Key Features

  • Designed for industrial spot-checking and field calibration.
  • Accurate measurement ranges from -70 to +30 °C (-94 to +86 °F) for dew point.
  • High-quality sensor optimized for low humidity measurement.
  • Low maintenance due to superior long-term stability.
  • Sensor withstands condensation, ensuring measurement accuracy.
  • Fast response, enhanced by Sensor Purge option.
  • Bluetooth interface for data transfer.
  • Data logging capability with a 4Gbytes micro SD card.
  • Compact, small, and lightweight design.
  • Rechargeable 3.7V Li-ion battery (3000mAh).
  • Automatic shutdown function.
  • Color screen design with an intuitive interface.
Infographic detailing eight core advantages of the DT-8321 and a product information table.
Figure 2: Eight Core Advantages and Product Information Overview.

This infographic highlights the meter's advantages such as low humidity and dew point measurement, condensation-resistant sensor, data logging, USB connection (for charging/data), automatic shutdown, and rechargeable battery. It also includes a detailed product information table for Relative Humidity, Dew Point, H2O PPM, and Temperature ranges, resolutions, and accuracies.

3. Product Overview

The DT-8321 consists of a main handheld unit and a detachable measurement probe. Familiarize yourself with the components before operation.

Key Description diagram of the DT-8321 main unit and probe with numbered parts.
Figure 3: DT-8321 Key Components.

This diagram labels the main unit and the probe with numbers indicating their functions.

Main Unit Components:

  1. LCD Color Screen
  2. Return/Exit Button
  3. Power On/Off Button (long press for on/off)
  4. Left Key
  5. MicroUSB Interface (for charging and data transfer)
  6. Enter/Select Button
  7. Up Key
  8. Hold Key
  9. Down Key

Probe Components:

  1. Interface to Measurement Probe
  2. Probe Interface
  3. Measuring Probe

4. Setup

4.1 Battery Installation and Charging

The DT-8321 uses a rechargeable 3.7V Li-ion battery (3000mAh). Ensure the battery is charged before first use.

  • Connect the device to a 5V power source using the Micro USB charging port (5) and the provided USB cable.
  • The battery indicator on the LCD screen will show charging status.
Rechargeable battery and Micro USB charging port details.
Figure 4: Battery and Charging Port.

This image shows the 3000mAh 3.7V lithium battery power supply and the Micro USB 5V charging port on the device.

4.2 Attaching the Probe

Connect the measurement probe (13) to the main unit via the probe interface (10) and (11).

5. Operation

5.1 Power On/Off

Long press the Power On/Off Button (3) to turn the device on or off.

5.2 Taking Measurements

Once powered on, the device will display real-time measurements on the LCD screen (1). The color screen provides an intuitive interface.

Close-up of the color screen interface displaying T, Td/f, and RH.
Figure 5: Intuitive Color Screen Interface.

The image displays the meter's color screen showing current temperature (T), dew point temperature (Td/f), and relative humidity (RH) readings.

5.3 Selecting Measurement Parameters

The device allows for optional display of multiple measurement parameters. You can select up to three sets of data to be displayed simultaneously.

  • Use the Up Key (7) and Down Key (9) to navigate through the menu options.
  • Use the Enter/Select Button (6) to confirm selections.
  • Available parameters include Temperature (T), Dew Point (Td/f), Relative Humidity (RH), and H2O PPM.
Screen showing optional display of multiple measurement parameters (Td/f, RH, H2O ppmv, T).
Figure 6: Parameter Selection Screen.

This screen shows checkboxes for various measurement parameters like Td/f, RH, H2O ppmv, and T, allowing the user to customize the display.

5.4 Data Logging

The DT-8321 features a flexible data recording function with an automatic recording interval that can be set. It can automatically generate a file for every 1000 sets of data recorded, saving up to 32 CSV files.

  • Access the data logging menu using the navigation keys.
  • Configure the recording interval as needed.
  • The device saves data to the internal 4Gbytes micro SD card.
Screen showing data logging interface with 'Hold Save Data' and CSV file information.
Figure 7: Data Logging Interface.

The screen displays 'Hold Save Data' with details like number of records, total capacity, current readings (T, Td/f, RH), and timestamp, indicating the device's data logging capabilities.

5.5 Data Transfer

Data can be transferred to a PC via the Bluetooth interface. Use the accompanying software to view and analyze the recorded data, which can be exported to Excel.

6. Maintenance

6.1 Sensor Probe Purification

The DT-8321 includes a sensor probe purification function for more accurate measurements. The probe can be cleaned by heating and drying the sensor to obtain more stable and accurate results.

  • Access the purification function through the device menu.
  • Follow on-screen prompts to initiate the cleaning cycle.
Diagram illustrating the sensor probe purification function with heating.
Figure 8: Sensor Probe Purification.

This diagram shows the probe tip with a heating element, illustrating how the sensor is heated and dried for purification to improve measurement accuracy.

6.2 General Care

  • Keep the device and probe clean and free from dust and debris.
  • Store the device in its gift box with carrying case when not in use.
  • Avoid exposing the device to extreme temperatures or harsh environments beyond its specified operating conditions.

7. Troubleshooting

  • Device not powering on: Ensure the battery is sufficiently charged. Connect to a 5V power source via Micro USB.
  • Inaccurate readings: Perform a sensor probe purification cycle. Ensure the probe is clean and not obstructed. Verify the device is operating within its specified measurement environment.
  • Data transfer issues: Ensure Bluetooth is enabled on both the DT-8321 and the PC. Check the connection status in the software.
  • Condensation affecting readings: The sensor is designed to withstand condensation. If issues persist, ensure the sensor purification function is used regularly.
Device in use, demonstrating the sensor's condensation resistance in an industrial setting.
Figure 9: Condensation Resistance in Action.

The image shows the DT-8321 being used in an environment where condensation might occur, demonstrating the sensor's ability to withstand such conditions without affecting measurement accuracy.

8. Specifications

ParameterRangeResolutionAccuracy
Dew Point-70 ~ +30 °C (-94 ~ +86 °F)0.1°±2 °C (±3.6 °F) for -60 ~ +20 °C
Relative Humidity0 ~ 100%0.1%RH<5%RH ±0.025%RH, >5%RH ±0.8%RH (±2%)
Temperature-10 ~ +60 °C (+14 ~ +140 °F)0.1°±0.2°C (±0.36 °F)
H2O PPM40-20000 ppm1±(7.3ppm + 8.3% reading)

Additional Specifications:

  • Dew Point Response Time:
    • Flow rate 0.2 m/s, 1 bar pressure, +20 °C (+68 °F) 63% [90%]
    • 0 -> -60 °C Td (32 -> -76 °F Td): 50 s [340 s]
    • -60 -> 0 °C Td (-76 -> 32 °F Td): 10 s [20 s]
  • Measurement Environment:
    • Temperature: -10 ~ 60 °C (14 ~ 140 °F)
    • Pressure: 0 ~ 20 bar (absolute)
  • Dimensions (HxWxD): 190mm x 75mm x 38mm
  • Weight: 320g
  • Interface: Bluetooth
  • Data Logger: 4Gbytes micro SD card
  • Display: LCD Digital Display
  • Material: Plastic, Metal
  • Battery: 3.7V Li-ion (3000mAh)
  • Charging Port: Micro USB (5V)
  • Warranty: 1 Year

9. User Tips

  • For the most accurate readings, allow the device and probe to stabilize in the measurement environment for a few minutes before taking a reading.
  • Regularly use the sensor purification function, especially after measurements in high humidity or condensing environments, to maintain sensor performance.
  • When logging data, ensure sufficient battery life and memory space on the SD card.
  • Keep the software on your PC updated to ensure compatibility and optimal data transfer with the device.

10. Warranty and Support

The CEM DT-8321 Portable Dew-Point Hygrometer comes with a 1-year warranty from the date of purchase. For technical support, troubleshooting assistance, or warranty claims, please contact your authorized dealer or the manufacturer's customer service. Keep your purchase receipt as proof of purchase.