Enable Safe Range

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Program Menu > Enable Safe Range

Temprecord loggers have the ability to compare the logged temperatures and humidity against upper and lower limits, and report whether the limits have been exceeded via the red and green LED on the logger.  In some situations, the logger must be started while the temperature/humidity is outside the limits and it is undesirable for this situation to be reported as a temperature/humidity outside of the limits.  Also, there are applications where a brief excursion outside the limits may be expected, and is not to be reported as an out-of-range error.

 

To accommodate these situations, Temprecord allows you to set a safe range enable, and an associated limit delay.

 

If the enable safe range option is not checked, logger samples are checked against the limits from the time when the logger is started.  If the option is checked, the temperature/humidity must enter the 'safe range' (i.e. it must be less than the upper limit and greater than the lower limit) before it will be checked against the limits.

 

If humidity only is being logged, then the above comments apply to humidity instead of temperature.

 

If both temperature and humidity are being logged, then both the temperature and humidity must be within their respective safe ranges

 

If this parameter is disabled with the G4 LCD logger the safe range delay will be set to zero for that channel when the logger is updated.  This is because the logger itself does not implement a separate control for safe range enable, but instead implements the function by setting the safe range delay to zero (which is equivalent).

 

In the Mk3 loggers, the safe range enable is shared with temperature and humidity channels, whereas the G4 LCD logger has separate enables for each channel.

 

If the enable safe range option is checked, comparison of the temperature (and/or humidity) values starts as soon as the number of samples taken inside the safe range exceeds the value specified in the limit delay parameter.  For example, if the limit delay is set to 5, the checking of temperatures and/or humidity against limits will not start until more than five successive samples have been recorded as inside the safe range.

 

To have comparison against the limits begin as soon as a sample is inside the safe range, set the limit delay to 0.

 

Enabling the safe range entry option does NOT mean that the logger does not start taking samples until the conditions for safe range entry are met.  Enabling safe range entry means that the samples taken are not COMPARED against the limits until the conditions for safe range entry are met.  The logger still takes samples from the time the start delay expires (or from the start time and date, if this is enabled).

On the LCD logger the behaviour of the LED's when limits are transgressed is configurable - i.e. when you program a logger you can determine whether the LED's indicate the state of the limits.  See Enable Status LEDs for more information.

See also:

Limit delay

Lower and upper limits

 


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