Logmore loggers preserve collected measurement data in dynamic QR codes. There is a limit to how much data can fit in one QR code and how much data can fit in the logger's internal memory. The limit is mainly defined by the logger's configuration — available sensors and measurement intervals.
How much data fits in one QR code?
Due to the compression of data the number of measurements in a QR code varies. Normally one QR code fits approximately 3000 measurements, but it's common to see numbers between 1000 and 5000 measurements. When the limit is reached the oldest measurement from the QR code is archived into a history QR code, while the incoming data is stored in the new QR code. Once you scan the history QR code, the historic data is also uploaded to the Cloud.
Check this guide on how to estimate the data fitting in one QR code to prevent history QR codes from being generated.
How much data fits in one data logger?
Logmore's multi-use loggers can fit up to 41000 measurements. If the logger remains unscanned for a critically long period of time, the measurement data will be erased as the internal memory gets filled with history QR codes. The period of time during which a logger can go unscanned depends on the measurement intervals and activate sensors. We recommend scanning the logger regularly to preserve measurement data safely in Logmore Cloud.
This graph helps you estimate how the logger's memory is filled depending on the measurement interval for one sensor.
| Measurement interval (in minutes for one sensor) | Days before the logger is full |
| 15 minutes | 208 days |
| 30 minutes | 417 days |
| 60 minutes | 833 days |
| 120 minutes | 1667 days |
What happens when the internal memory is full?
The loggers utilize a First-In, First-Out (FIFO) memory overwrite mechanism. Upon reaching capacity, the most recent measurement replaces the oldest.
Rest assured, your history and data remains secure in the Logmore Cloud as long as the QR code was scanned prior to the overwrite.
Use calculator to estimate the time before the logger's memory gets full
For detailed specifications, check our Logmore calculator. The calculator shows how many new measurements the logger records per day with given settings. Knowing that the memory capacity of one logger is around 41000 measurements, you can check how many days the logger can go unscanned.
- Go to https://web.logmore.com/batterycalc.
- In Settings, fill in the desired measurement intervals for available sensors.
- In Measurements, you will see the amount of new measurements recorded per day with the given settings.
- Divide 20000 by this number. The result is the number of days it will take before the logger's memory gets full.
In the example above: 41000/192=213 days with the 15-min measurement interval for light and temperature sensors. - You will also see the number of days fitting in one QR code with given measurements. This is how many days it will take before a history QR code is generated.
- Adjust the Settings to find out the optimal configuration for your loggers.
- To configure the measurement interval of a logger, check this guide on logger configuration.
- Please note that these calculations are approximate. We recommend planning your operations in a way that allows for regular scanning of the data loggers. Once the measurement data is uploaded to Logmore Cloud, it is safely stored there.