TempDot Plus Time-Temperature Labels FAQs
How long is the shelf life after I activate the label?
If an activated label is kept below its threshold temperature, it will maintain a 2-year shelf life.
Where can I find instructions on how to activate the TempDot Plus label?
Activation instructions are on the product package and also on the product specification sheets which can be found on our website
What should I do if I press the activation button and the word “ON” does not appear in the activation window?
Ensure the label is activated in an environment above threshold temperature. Press the activation button again to make sure all the dye has been released from the blister. Wait a few minutes and if the word “ON” still does not appear, discard the label and do not use it.
What should I do if more than 5 minutes have passed after activation and I haven’t put the label in an environment below its threshold?
The run out process will start and there might be colored dye starting to show in the large, white indicator window. The blue dye must solidify to stop further progression across the white indicator window, so the label must immediately be placed at or below the stop temperature which is listed in the activation instructions on the product specification sheet.
What is the difference between threshold temperature and stop temperature?
Threshold temperature is the temperature at which the colored dye melts and starts migrating across the white indicator window to track accumulated temperature above the stated threshold. Stop temperature is the temperature at which the colored dye solidifies and stops migrating across the white indicator window.
Why is stop temperature lower than threshold temperature?
Freezing point of a liquid is always lower than its melting point. Freezing occurs when the first crystals form, which is typically at a temperature lower than its melting point, therefore the ‘stopping point’ (stop temperature) is lower than the precise ‘starting point’ (threshold temperature). TempDot Plus works by diffusion of liquids across a porous membrane, which is the white indicator strip visible in the large window. The behavior of the liquid within this membrane, and all relevant factors are taken into account when the threshold temperatures and stop temperatures were defined for each model.
Why is ‘Stop Temperature’ important?
Activation of the TempDot Plus label must be done when the colored dye is in liquid form in order to get positive confirmation that it was successfully activated. After the word “ON” appears in the activation window, the label must be placed at or below the designated stop temperature to keep the dye from migrating to the indicator window. After the dye is solidified, the label can be applied to a product or package above stop temperature and below the threshold temperature, and should stay in a controlled environment that is also below threshold temperature.
Can I activate labels above their response temperature and immediately store them below stop temperature so that I can apply to products later, as needed?
Yes, as long as the place of storage is at or below the stop temperature of the particular model. This is actually how some customers are using TempDot Plus. Activate the labels according to instructions (see product package or specification sheet), when the word ‘ON’ appears in the activation window, immediately place them in storage below threshold temp. When ready to send a product through the supply chain, apply the TempDot Plus to product that has already been pre-cooled, packaged, and held in a temperature controlled environment below threshold. Every time the label is exposed above its stated threshold temperature, the dye will melt and migrate across the white indicator window to show the amount of accumulated time above threshold in Degree*Hours.
What happens if I apply an activated label to product or package that has not been pre-cooled?
If you apply a label to a product that is not yet pre-cooled and then place it in a temperature controlled environment, then the temperature of the surface to which you have adhered the label can affect its response. In other words, the product is going from room temperature to a lower temperature it still needs time to acclimate to the controlled environment. This can cause the label to start indicating temperature abuse if the temp of the surface it is touching is above the threshold of the label.
Does it matter what angle the label is applied to a surface, or the orientation of the surface where the label is applied?
TempDot Plus labels are not affected by gravity and can work in any position. The label or the surface they are adhered to can be oriented horizontally, vertically, face up or face down.
The label has a stated time accuracy ±15%, can you give an example?
For 2 hours of elapsed time this means an accuracy of ±18 minutes under isothermal conditions. So it could be within 1 hour and 42 minutes or 2 hours and 18 minutes. This accuracy is better than most other products on the market, which usually measure time accuracy by the distance the colored dye travels along the indicator strip (e.g. most other products are ±9% of distance which equals accuracy of 18% to 20% on time). TempDot Plus gives a much more accurate time monitor than other labels on the market.
What are isothermal conditions?
Most standard TempDot Models have the activation blister on the front, top of the label, directly above the activation window. Model 51053 has a much longer run out time as compared to other models, so it requires a longer progress indication window to accommodate the time markers showing accumulated temperature abuse from 1, 2, 4, 8, 12, 24, and up to 48 hours. The activation button is located on the back of the label in order to make room for this.