Data Logging Duration

28.07.2015 15:26

"How long will my data logger record for?"

The Main Factors That Affect Logging Duration

Itís about Tinytag data loggers here. Tinytag Explorer software will show a user how long a data logger will record for at the bottom of the Launch page.
As different settings are changed by the user, this logging duration will update automatically.
The main features and settings that determine the logging duration of a data logger are its memory size and the logging interval it is programmed to record at.
Memory Size
Our data loggers have memory sizes ranging from 8,000 readings, for Talk and Transit loggers, up to 64,000 readings in our Re-Ed loggers (all Ultra, Plus and View loggers have a reading capacity of between 30,000 and 32,000 readings).
For dual channel data loggers, that are set to record two properties at the same time, this reading capacity is split between the two channels.
Logging Interval
Most data loggers can be set for a logging interval of between one second and once every ten days (though, typically, most customers donít tend to use logging intervals over once an hour or in some cases once a day).
Switching between seconds mode and minutes mode has no effect on the logging duration; selecting minutes mode allows you to download, or check current readings, whilst a data logger is recording.
Other Logger Settings That Affect the Logging Duration
Measurement Options
By default, data loggers will be set to record at the end of each logging interval.
In data loggers that can record more than one property it is possible to turn off one of the channels to maximize the logging duration of the other. For example, this may allow the longer collection of temperature only data from a temperature and relative humidity data logger where the humidity data isnít required.
Most loggers in our current range can also be set to record minimum and/or maximum values over a logging interval*.
When set to record minimum and/or maximum data, loggers will check their inputs once every second (in seconds mode) or once every minute (in minutes mode) and then store the minimum/maximum value at the end of the logging interval.
This means that if a customer is only interested in min/max data, they can set the logger to store data once every hour, but the logger will actually be checking the values on its input(s) every second or minute depending on how it has been configured.
*Older, non- "2" range data loggers, can only be set to record one property per-channel at a time (so either a reading at the end of a logging interval, the minimum value or the maximum value; not combinations of the three).
Stop Options
Most data loggers have three stop modes:
Stop when fullĖ By default units will stop when their memory is full, but they can also be set to run continuously (over-writing their oldest readings) or to stop after a set number of readings. Setting a logger to stop when full preserves the data at the beginning of a logging run if the user doesn't download the logger before it fills its memory.
Run indefinitely- Leaving a data logger to record continuously means the most recent data recorded by the logger can be viewed, but the oldest data will be lost because the unit will record over it once its memory is full.
Stop after Ö readings- Stopping a data logger after a set number of readings obviously limits the amount of time a logger will record for.
If customers are only looking for fault conditions, such as a fridge going over temperature, setting a logger to record continuously, in minutes mode with latching alarms set, allows the user to leave the logger recording and only download it when its red LED starts to flash (using latching alarms means the LED will continue to flash should an out of range event occur over night or at the weekend when no one is around to witness it).
The table below gives an idea of how long a data logger will record for a given memory size.
Logging Interval
Reading capacity
1 Second
2h †13m
4h †31m
9h †3m
1 Minute
5d †13h
11d† 7h
22d† 15h
5 Minutes
27d †21h
10 Minutes
15 Minutes
30 Minutes
1 Hours
The above table assumes the data logger is used as supplied, with the stop options set to stop when full and the loggerís default measurements enabled.
For dual channel data loggers, the reading capacity will be reached in half the time shown.
If the logger is set to record minimum and/or maximum data the logging duration will change again.
Battery Life
Battery life will generally not be a factor in determining how long a logger will record for, unless a logger is being used for a long term project where it cannot be downloaded regularly.
When recording in multiples of one second, the battery life of all data loggers should last just over a year. When recording in multiples of one minute or more, most data loggers will record for at least two years (the main exceptions to this are the View 2 data loggers which, because of their displays, typically record for 15 to 18 months).
The effect of temperature on battery life can usually be ignored provided loggers are used within their quoted operating range (see product data sheets for this information).
Tinytag Radio Data Loggers
In a radio system where data loggers form part of a stable mesh, the data being recorded by the loggers will be stored on the computer running the Radio Gateway.
If a logger cannot communicate with the Gateway, it will record data locally.
The "off-line" duration that a radio logger will record for will depend on the number of channels it has, but as with our standard data loggers, when a data logger is configured, Tinytag Explorer will tell the user what it's "off-line" storage capacity is.
Tinytag Energy Data Loggers
Energy data loggers can be configured to record in a number of different ways (from single phase current only to three phase current with voltage and power consumption information).
Also, the Energy Logger has been designed to be started and stopped in the field, so Tinytag Explorer does not display a logging duration figure for this type of logger.
An Energy Data Logger set to record three phase current with voltage and power consumption information, on a 15 minute logging interval, will record for nearly four months before filling its memory.
If less parameters are being recorded (e.g. single phase current only) the logger will record for a significantly longer period.
When plugged into the mains an energy logger will power itself from the mains, but if it is being used to monitor current only it will be powered by batteries that have a typical life of 60 days.
Further Information
Further information on the different settings a logger can be programmed with, and what effect they have, can be found in the quick start guide for Tinytag Explorer and the software's Help file (Help >> Contents).
Further information on data logger memory sizes and features (min/max recordings and stop modes etc.) can be found on our product data sheets.

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