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Load Sensed Timing probe

What is Load Sensed Process Timing?

Find out more about this popular autoclave option, when you need it and why...

Load Sensed Process Timing is an optional extra which can be added to any Astell autoclave. It is particularly recommended for fluid loads, e.g. culture media, where a precise sterilization temperature is likely to be critical. In addition waste (‘discard’) loads will generally benefit from the inclusion of this option, to ensure that all parts of the load are reaching the necessary temperature.

Why Load Sensed Process Timing is recommended

Everything you put inside an autoclave has thermal mass. This means that a load (the items you want to sterilize) will always heat up more slowly than the sterilizer chamber itself. If this is not allowed for in the timing parameters of the cycle program, the load will not be subject to the correct conditions, i.e. it will be exposed to the set temperature for too short a time to achieve complete sterilisation. Load Sensed Process Timing (LSPT) avoids this problem.

Load Sensed Process Timing allows the sterilization cycle to be controlled via the temperature achieved in the centre of the load. To do this a ‘wandering’ probe is situated within the autoclave chamber and must be inserted into the load, or a load simulator (a replica of the items and contents being sterilised). Typically with media loads, the Load Sensing probe is placed within one of the bottles of media, or in a bottle of water of similar volume.  When sterilizing ‘discard’ the probe should be placed in a suitable container in the centre of the load or, if specialist discard containers are used, (and this is preferable), there is ofted a custom-designed compartment within the container to accept the probe, and prevent it from adhering to plastic waste etc.  The autoclave then initiates the sterilization period once the probe reaches the programmed threshold temperature. The setting and operation of load sensed process timing is controlled via Astell’s standard-fit Colour Touchscreen controller.

The position of the load sensing probe is very important. The probe must be in the same place for running sterilisation cycles as it was when the cycle was first set up and tested. It is recommended a laboratory procedure is created to document and standardise the positioning of the probe.

Correctly positioned, the load sensing probe detects the temperature within the load and so will ensure that the load experiences the set conditions for the set time. If it is just put to one side of the chamber instead of in the load, then fluid loads will experience only a very short time at the set sterilizing temperature, or may not reach sterilization at all.

The load sensing probe Astell provides with the LSPT option is typically a 5-6mm diameter PT100 flexible type. Alternative probes may be available for non-standard applications, please Contact us for further details.

To explore the full range of options available to each Astell autoclave, select the relevant Products page and click the ‘View Product Options’ button.

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