1. Introduction
The Mastech MS6300 is a versatile digital environment multimeter designed to measure various environmental parameters. This device combines the functions of a Sound Level Meter, Luminometer, Relative Humidity Meter, Temperature Meter, Anemometer, and Air Flow Meter into a single, portable unit. It is suitable for a wide range of applications, including environmental monitoring, industrial hygiene, and HVAC system analysis.
This manual provides detailed instructions for the safe and effective operation, maintenance, and troubleshooting of your MS6300 meter. Please read this manual thoroughly before use and keep it for future reference.
2. Safety Information
To ensure safe operation and service of the meter, follow these instructions:
- Read all safety information and operating instructions before using the meter.
- Do not operate the meter if it appears damaged or if the protective casing is compromised.
- Keep the meter away from water, dust, and extreme temperatures.
- Do not attempt to repair or modify the meter. Refer servicing to qualified personnel.
- Remove batteries if the meter is not used for an extended period to prevent leakage.
- Dispose of batteries properly according to local regulations.
Battery Safety
- This device uses one 9V 6F22 battery (not included).
- Ensure correct polarity when installing batteries.
- Do not mix old and new batteries, or different types of batteries.
- Do not expose batteries to excessive heat or fire.
3. Product Overview
The Mastech MS6300 is designed for ease of use with a clear LCD dual display and intuitive controls. Below are the key components and their functions:

- Windproof Ball: Covers the microphone for sound level measurements.
- Power Switch: Turns the device on/off.
- Set Button: Used to select AVG/MAX/MIN/DIF (MAX-MIN) modes.
- Temperature and Humidity Sensor: Measures ambient temperature and relative humidity.
- Illumination Button: Activates the light sensor.
- Backlight Button (BL): Toggles the display backlight.
- Wind Speed and Air Volume Sensor: Measures air flow and wind speed.
- LCD Display: Shows measurement readings and unit indicators.
- UNIT Button: Changes measurement units (e.g., °C/°F, m/s/knots, LUX/FC, dB(A)/dB(C), CMM/CFM).
- HOLD Button: Freezes the current reading on the display.
- MODE Button: Cycles through different measurement functions (Sound Level, Luminometer, Humidity/Temperature, Anemometer, Air Flow).
- Tripod Mount: Located at the bottom for stable placement.


4. Setup
4.1 Battery Installation
- Locate the battery compartment cover on the back of the meter.
- Use a screwdriver to open the battery compartment.
- Insert one 9V 6F22 battery, ensuring the correct polarity (+/-).
- Replace the battery compartment cover and secure it with the screw.
Note: Batteries are not included with the product.
4.2 Initial Power-On
Press the POWER button to turn on the meter. The LCD display will illuminate, and the meter will perform a self-test before entering the default measurement mode.

5. Operating Instructions
5.1 General Operation
- Power On/Off: Press the POWER button.
- Backlight: Press the BL button to turn the display backlight on or off.
- Data Hold: Press the HOLD button to freeze the current reading. Press again to release.
- Mode Selection: Press the MODE button to cycle through the different measurement functions: Sound Level, Luminometer, Humidity/Temperature, Anemometer (Wind Speed), and Air Flow.
- Unit Selection: In each mode, press the UNIT button to change the measurement units.
5.2 Sound Level Measurement
- Turn on the meter and select Sound Level mode using the MODE button.
- Press the UNIT button to select between dB(A) or dB(C) weighting.
- Position the microphone towards the sound source.
- The sound level will be displayed on the LCD.
- Use the SET button to cycle through AVG (Average), MAX (Maximum), MIN (Minimum), and DIF (Difference between MAX and MIN) values.
5.3 Luminance Measurement (Luminometer)
- Turn on the meter and select Luminometer mode using the MODE button.
- Press the UNIT button to select between LUX or FC (Foot-Candle) units.
- Ensure the light sensor (located near the microphone) is exposed to the light source.
- The illuminance value will be displayed.
- Use the SET button for AVG/MAX/MIN/DIF values.
5.4 Humidity and Temperature Measurement
- Turn on the meter and select Humidity/Temperature mode using the MODE button.
- The relative humidity (%RH) and temperature will be displayed simultaneously.
- Press the UNIT button to switch between Celsius (°C) and Fahrenheit (°F) for temperature.
- Use the SET button for AVG/MAX/MIN/DIF values.
5.5 Anemometer (Wind Speed) Measurement
- Turn on the meter and select Anemometer mode using the MODE button.
- Press the UNIT button to select desired wind speed units (m/s, ft/min, knots, km/h, mph).
- Position the wind speed sensor (fan) directly into the airflow.
- The wind speed will be displayed.
- Use the SET button for AVG/MAX/MIN/DIF values.
5.6 Air Flow Measurement
- Turn on the meter and select Air Flow mode using the MODE button.
- Press the UNIT button to select between CMM (Cubic Meters per Minute) or CFM (Cubic Feet per Minute).
- Before measuring air flow, you must input the area of the duct or vent. The meter supports area range 0~999.9m² or 0~999.9ft². Refer to the full manual for detailed instructions on area input.
- Position the wind speed sensor into the airflow.
- The air flow rate will be displayed.
- Use the SET button for AVG/MAX/MIN/DIF values.
6. Features
- Auto & Manual Ranging: The meter can automatically select the appropriate measurement range or allow manual selection for specific applications.
- Auto Power Off (APO): To conserve battery life, the meter automatically turns off after a period of inactivity.
- AVG/MAX/MIN/DIF (MAX-MIN): Provides statistical analysis of measurements, showing average, maximum, minimum, and the difference between maximum and minimum readings.
- A / C Weighting Indication: For sound level measurements, allows selection between A-weighting (approximates human ear response) and C-weighting (flat response).
- Data Hold: Freezes the current reading on the display for easy recording.
- Display Backlight: Illuminates the LCD for clear visibility in low-light conditions.
- Low Battery Display: An indicator on the display warns when the battery level is low, prompting replacement.
7. Specifications
The following table details the technical specifications of the Mastech MS6300 Multifunctional Environment Meter:

| Parameter | Range | Resolution | Accuracy |
|---|---|---|---|
| Temperature | -10~60℃ 14~140℉ | 0.1℃ 0.1℉ | ±1.5℃ ±2.7℉ |
| Relative Humidity | 20%~80%RH <20%~80%RH | 0.1%RH 0.1%RH | ±3.0%RH ±5.0%RH |
| Sound Level | 30~130dB(A) 35~130dB(C) | 0.1dB 0.1dB | ±1.5dB ±1.5dB |
| Illuminance | 0~2000LUX X10 (20000) X100 (50000) | 1LUX 10LUX 100LUX | ±(5.0%+10) ±(5.0%+10) ±(5.0%+10) |
| Wind Speed | 0.5~30m/s 1.8~72km/h 96~3942ft/min 0.9~38.9knots | 0.1m/s 0.1km/h 1ft/min 0.1knots | ±(3.0%+10) ±(3.0%+10) ±(3.0%+10) ±(3.0%+10) |
| Air Flow (CMM) | 0~999900CMM | 0.1CMM (<1000CMM) 1CMM (>1000CMM) | ±(3.0%+10) |
| Air Flow (CFM) | 0~999900CFM | 0.1CFM (<1000CFM) 1CFM (>1000CFM) | ±(3.0%+10) |
General Specifications:
- Power Supply: 1x 9V 6F22 Battery
- Product Size: 280mm x 89mm x 50mm / 11.0" x 3.5" x 2.0"
- Product Weight: 433g / 0.95lb
- Certifications: CE, RoHS
8. Maintenance
- Cleaning: Wipe the meter with a dry, soft cloth. Do not use abrasives or solvents.
- Storage: Store the meter in a cool, dry place. If storing for an extended period, remove the battery.
- Sensor Care:
- Keep the microphone (windproof ball) clean and free from debris.
- Ensure the light sensor is not obstructed.
- Keep the wind speed/air volume sensor (fan) clear of any foreign objects to ensure accurate readings.
- Avoid touching the temperature and humidity sensors directly.
- Battery Replacement: Replace the 9V battery when the low battery indicator appears on the display.
9. Troubleshooting
- Meter does not power on:
- Check if the battery is installed correctly with the right polarity.
- Replace the 9V battery with a new one.
- Inaccurate readings:
- Ensure sensors are clean and unobstructed.
- Verify the meter is in the correct measurement mode and units.
- Allow the meter to stabilize in the environment before taking readings, especially for temperature and humidity.
- For air flow, ensure the correct area has been input.
- Display is dim or flickering:
- Replace the battery.
- Check if the backlight is activated; deactivate if not needed to save power.
10. User Tips
- Stable Measurements: For best results, especially with wind speed and air flow, use the included tripod to keep the meter stable and ensure the sensor is directly facing the airflow.
- Environmental Acclimation: When moving the meter between environments with significant temperature or humidity differences, allow a few minutes for the sensors to acclimate to the new conditions before taking critical measurements.
- Regular Cleaning: Periodically clean the wind speed sensor (fan) and light sensor to prevent dust and debris from affecting accuracy.
11. Warranty and Support
The Mastech MS6300 Multifunctional Environment Meter is designed and manufactured to high-quality standards and is CE and RoHS certified. For any technical support or warranty inquiries, please refer to the contact information provided by your retailer or the official MasTech website.
Please retain your purchase receipt as proof of purchase for warranty purposes.





