cd50 M390 Sound Level Meter

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www.cd50.net/m390/

User Manual

TUTORIAL VIDEO ON HOW TO USE
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INTENDED USE

Thank you very much for your patronage and choosing our products. Before you use this product, please read this manual carefully as it will familiarize you with the correct operating procedure.

PRODUCT FEATURES

• Measurement range: 30~130dB.
• Includes A/C/Z frequency weighting selection and FAST/SLOW time-weighted options.
• Data hold and MAX/MIN/AVG measurement functions
• Supports data download and real-time PC connection, displaying data sheets and charts. Allows exporting and printing of data sheets and charts. PC software compatible with Win7, Win8, Win10.
• Allows separate setting of upper and lower limits.
• Audible and visible alarm
• Analog bar scale indication and low battery alert function

SPECIFICATION

• Micro phone High precision 1/2 inch micro phone
• Range 30~130dB
• Measuring level 30~70dB, 60~90dB, 80~110dB, 100~130dB
• Resolution 0.1dB
• Accuracy ±1.5dB(sound pressure reference, 94dB@1kHz)
• Frequency weighting A/C/Z weighting
• Time weighting 0.125s, SLOW: 1s
• Sampling rate 2 times/s
• Frequency response 31.5Hz~8kHz
• Analog bar One scale represents 1dB
• Display 4 digit, max 1999
• Ambient temp Range: 0~60°C, Accuracy: ±2°C
• Over range “OVER-HI”, “UNDER~LO”
• Data logger 1999 groups
• Synchronous update  Refer to PC information for program update
• Auto power off  15 mins (can be canceled)
• Working environment  -10~50°C, max 80%RH, indoor altitude <2000m
• Storage environment -10~50°C, max 70%RH ( battery removed)
• Product size  229 x 70 x 35mm
• Screen size  53 x 44mm
• Weight Approx. 215g (battery not included)
• Power 3 x 1.5V AAA (LR06) battery USB micro interface 5V

METER DESCRIPTION

DISPLAY

BUTTON FUNCTION DESCRIPTION

• Press it to power the meter on/off
  NOTE: When powered via USB, manual shutdown is not possible
• Press and hold it for 2 seconds to start/stop recording
• While recording, press it to pause or continue recording
• Press it to switch the measurement range among 30~70dB, 60~90dB, 80~110dB, 100~130dB
• Press it to toggle between FAST and SLOW weighting
• Press it to cycle through MAX/MIN/AVG mode and display the value in the sub-window.
  In setting mode, a single press decreases the value, while holding it down enables fast adjustment.
  NOTE: The value is calculated from the moment you press the button.
• Press to switch between A/C/Z weighting.
• Press and hold for 2 seconds to switch the temperature unit.
• In setting mode, a single press increases the value, while holding it down enables fast adjustment.
• Press it to hold/release the current measured value.
• Press and hold it for 2 seconds to access/exit the setting mode.
• While in setting mode, press it to cycle through Hi/Lo limit alarm setting, set meter’s recording interval and view the stored data.

SETTING MODE

1. Hi limit alarm setting
   Under measurement mode, press and hold the button to enter HI limit alarm setting. Default value is 130dB. Use buttons to adjust the alarm value. Press to confirm and proceed to the next setting.
2. Lo limit alarm setting
   Default value is 30dB. Use buttons to adjust the alarm value. Press to  confirm and proceed to the next setting.
3. Set meter’s recording interval
   Default is 5s, adjustable between 1s, 5s, 10s, 30s, 1min, 30mins, 1h, 12h, and 24h. Use keys to select the desired recording interval. Press to confirm and proceed to the next setting.
4. View the stored data in the meter
   The MEM symbol displays, showing recorded groups at the bottom. Navigate records with keys. Press to confirm and exit.

NOTE: Under this menu, press and hold the button simultaneously for 2s to clear  up the stored data.

DISABLE AUTO POWER OFF FUNCTION
The auto power off function is enabled by default, the screen shows the symbol when the meter is turned on. This feature is activated only after 15 minutes of inactivity. However, when the meter is USB powered, even if the auto power off is enabled, the meter will not shut off automatically.

To disable Automatic Power Off: Before startup the device, press and hold button, then simultaneously press the button until APo oFF icon appears on the screen.  symbol will disappear after disabling the Auto Power Off function.

NOTE: The auto power off function will restore when restart the meter.

DATA LOGGING AND PC INTERFACE

1. Types of data recording
   • Data logging on the software: Automatically log data onto the software where the number of data points is unlimited.
   • Data logging on the meter: Automatically log up to 1999 readings onto the meter via push-button press.
2. Data logging on the software
   • Install the software. Please download and install the free EnvironmentalTester software from the QR code or URL below.
     Scan the QR code: www.cd50.net/m390/
   • Double click Environmental Tester to open it. Connect the decibel meter to the computer using the provided USB cable . The software interface should appear as shown below, indicating that it is now ready for use.
3. Data logging on the meter
   • Set the desired sampling rate (refers to Setting Mode-Section 3)
   • Long press the button over 2 seconds to start/stop recording. REC symbol will be  flashing when in recording mode.
   • Launch the software and then connect the decible meter to the computer.
   • Click upload and wait few seconds; the data points stored in the meter will be synchronize to the software.
   • To export the data points, click the “file” button located at the top of the software and then select to save in bpm/table format
   • Configure parameters. Click menu button located at the top of the software. A dialog window will appear where you can set the sampling rate and alarm threshold. Confirm your selections by clicking OK. Sampling rates available: 1s, 2s, 5s, 10s, 30s, 60s, 30min, and 1h. NOTE: The parameters specified here are intended for data logging within the software system and are not configured to automatically synchronize with the meter.
   • Press the Start / pause button located at the left of the software to start / stop real-time recording.
   • To export the data points, please click the “file” button located at the top of the software and then select to save in bpm/table format.

IMPORTANT!!!
To prevent the loss of real-time data points recorded in the software it is necessary to export them before exiting the program or uploading the data points stored in the meter. Failure to do so will result in the deletion of all recorded data points in the software.

BATTERY REPLACEMENT

• When the battery level is low, an empty battery icon will appear  , indicating that the  batteries need to be replaced.
• To replace the batteries, please follow these steps:
  1. Remove the battery compartment cover.
  2. Replace the old 3 AA batteries with new ones.
  3. Pay close attention to the battery polarity when placing the new batteries into the compartment.
• Make sure to fasten the compartment cover securely after replacing.

MAINTENANCE

Avoid prolonged measurements in high-temperature, high-humidity conditions. Remove the battery if the device won’t be used for an extended period.
If your device malfunctions and requires repair confirmed by the manufacturer or dealer, provide a written description of the failure and a packing list. Package the item securely for protection.

Frequently Asked Questions

• Q: How do I change the measuring level on the sound level meter?
  A: You can change the measuring level by selecting the appropriate option in the settings menu.
• Q: Can I use the sound level meter for outdoor measurements?
  A: Yes, ensure to consider the ambient temperature and protect the device from moisture during outdoor use.
• Q: What is the purpose of the data logger function?
  A: The data logger function allows you to record and analyze sound level measurements over time.

Documents / Resources

cd50 M390 Sound Level Meter [pdf] User Manual M390_E, M390 Sound Level Meter, M390, Sound Level Meter, Level Meter

References

• User Manual