Procedure for the Cryoguard Activation Tool Used for Cryoguard Thermal Exposure Indicators on a Freezer Cane

1. Place a Cryoguard Thermal Exposure Indicator in an end slot of the freezer cane so that the pin of the indicator is either facing out towards the end of the cane or facing in towards the middle of the freezer cane with enough space to fit the activation tool plates. The indicator can be placed upright or upside down in either end of the freezer cane depending on the application in which it is being used as seen below in the figures.

This tool allows for activation of indicators in any of the four possible positions. The upper two images show the positioning of the indicator in the top of the freezer cane, while the lower two images show the positioning of the indicator in the bottom of the freezer cane.

2. Freeze the indicator on the cane in liquid nitrogen for the appropriate length of time based on which indicator is being used. See Package Insert to determine the length of time needed to freeze the indicator.

3. After the necessary freezing time has passed, remove the freezer cane and indicator with the activation tool in hand, ready for use. The tool should be held so that the base is in the palm of the hand with the thumb holding it in place and fingers resting on the lever as shown below without an indicator already inserted into the tool.

4. Affix the freezer cane on the activation tool so that the indicator is in the tool between the two plates and the unused length of the freezer cane is pointed away from the hinge of the activation tool. Both plates of the activation tool have depressions for the pin for versatile activation of the indicator, thus allowing for the indicator to be activated in any of the four positions used on the freezer cane as shown below in the figure.

The upper two pictures show a demonstration of the indicator in the bottom of the freezer cane, while the lower two pictures show the indicator in the top of the freezer cane.

5. Adjust the indicator using the freezer cane so that the pin is directly in the depression of the plate. The indicator should be positioned as shown. The freezer cane was removed for obtaining clear images only. These images demonstrate how the indicator can be placed in either direction in the tool.

6. Wait for the indicator to slightly thaw if needed (thawing time varies for the different types of indicators) for easier, less damaging activation. See Package Insert to determine the length of time needed, if any, to thaw the indicator before activation.

7. Apply gentle, steady pressure to the lever of the activation tool using the fingers until the pin is completely pushed into the indicator housing and is flush with the bottom of the indicator. Below is an image that demonstrates what an activated indicator looks like in the activation tool. The images show how the plates become flush with the indicator housing when the lever is completely pressed. The lever moves the inner plate toward the outer plate so that there is only enough space for the indicator, and there are no gaps between the indicator and plates. Do not remove the freezer cane during this process. The images are for visual purposes only.

*Note: Applying high pressure quickly will result in damages to the pin and/or indicator causing it to be unusable

8. Immediately refreeze the indicator in liquid nitrogen on the freezer cane for an appropriate amount of time based on which indicator is being used. See Package Insert to determine the length of time needed to freeze the indicator after activation. This step is especially important for M-135 and M-150 indicators due to the fact that they thaw quickly in room temperature, thus causing a premature color change.

9. After refreezing, the indicator is ready for use. Place the indicator in the environment of intended use.

**Be sure to handle indicators with insulated gloves when frozen in order to prevent premature color change. Safety glasses should also be used at all times.