Notice regarding malfunctions when using batteries with the LA-7200/LA-7500/LA-7700 sound level meters

Thank you for your continued patronage of Ono Sokki products.

We would like to reiterate that we have added the LA-7700 sound level meter to the information we provided on March 10, 2021.
There are no changes other than the addition of supported models.

We have recently discovered that when using the LA-7200/LA-7500/LA-7700 sound level meters with batteries, measurement errors may occur due to voltage drops caused by battery depletion. We will implement a fix to rectify this issue, but since the circuit changes resulting from the hardware modification require type approval, it will take some time. We sincerely apologize for any inconvenience this may cause our customers. We would like to inform you of the measures we will take and address for our customers as follows.

Target Products

Details of the problem

When using the LA-7200/LA-7500/LA-7700 sound level meter with batteries, the voltage will drop as the batteries are depleted, and the sound pressure level will be displayed as higher than the actual level when the voltage falls within a certain range (4.93 V to 4.98 V).
When using new LR6 alkaline batteries, a malfunction will occur approximately 5 hours after starting operation.
For about an hour after the event occurs, the measured value may be output as higher than the normal value, and then it will return to normal.
Even with USB power supply, voltage variations may cause malfunctions.
No problems will occur when using the included AC adapter.

Cause of the malfunction

The problem lies with the power supply circuit components that generate power for the analog circuit from the battery voltage.

correspondence

We plan to take possession of the item and make the necessary repairs.
A circuit change will be required due to hardware modifications to the sound level meter, which necessitates a re-application for type approval in accordance with the Measurement Law. We will implement the modifications once approval is obtained.
Currently, we plan to begin accepting returns in August 2021, and will return the items after making the necessary corrections. We will inform you again once preparations are complete.
We apologize for the inconvenience, but please use the AC adapter until the issue is resolved.
Please refrain from using USB power supply, as it may cause malfunctions.
Customers who wish to use batteries are requested to update the firmware before use. If you would like us to perform the work, please contact your nearest sales office.
The firmware detects low battery voltage and displays a low battery warning and shuts down the device before any malfunction occurs, resulting in a shorter battery life of approximately 4 hours with new LR6 alkaline batteries. Furthermore, please refrain from using Ni-MH rechargeable batteries, as their low voltage will render them unusable in a short time.

How to update the firmware

1. How to obtain the firmware file

Please obtain the firmware file (LA7000Firmware.dat) from the LA-7000 series user page below.

If this is your first time logging in, please click [New Registration]. If you are already registered, please click [Login] to proceed to the LA-7000 series user page, and then download the firmware from that page.
Please save the downloaded file to the root directory of your SD card.

2. Firmware update procedure

For detailed instructions on the firmware update procedure, please refer to the update procedure on the download page, or to page 219 of the Basic Operation section of the instruction manual, "Firmware Update," or to the firmware update procedure in the installation guide.

3. How to check after the update

Please check the updated version as follows: Check the "CPU Version" displayed under [Menu] - [General] - [Information/Update]. Confirm that the updated version is "4.0.1".

4. Others

If you request calibration or correction of your sound level meter, we will confirm with you and perform a firmware update during the calibration and correction process.
If you have any questions regarding the update, please contact your nearest sales office.

Regarding inquiries

For inquiries regarding the effects of the measurements, please contact us using the inquiry form below or through our customer support center.

If you have any questions, please contact our customer service department or your nearest sales office.