ANY-maze Help > I/O devices supported by ANY-maze > Test equipment designed specifically for ANY-maze > The Orofacial pain assessment device (OPAD) cage > OPAD reference information > OPAD cage configuration - Calibration page

OPAD cage configuration - Calibration page

The weight sensor was only included in early versions of the OPAD device. If the configuration window does not have a 'Calibration' tab, it simply means that your OPAD does not include a weight sensor.

Introduction

The OPAD cage includes a weight sensor which measures the amount of liquid consumed by the animal during a test. This weight sensor is quite sensitive, having a resolution (and accuracy) of 100mg. To maintain this level of accuracy, it is necessary to periodically recalibrate the sensor against a known weight - we recommend that you do this once a month during normal use.

Calibration is performed using the Calibrate tab of the OPAD cage configuration window (see figure 1), which is accessed either from the I/O page or from the Configure... button on the I/O device settings page of the protocol.

Figure 1. The 'Calibration' page of the OPAD cage configuration window.

When to recalibrate

You should recalibrate your OPAD cage weight sensor under the following circumstances:

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When you first set up the cage - indeed, you can't use it until you calibrate it for the first time

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Recalibrate periodically during normal use - once a month is recommended.

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If you don't use the cage for a long period, recalibrate before performing any tests.

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If you move the cage to a different location, recalibrate before performing any tests.

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If you want to use the cage in an ambient temperature that is more than 10°C different to the temperature at which it was calibrated.

Step-by-step instructions

First you need to open the OPAD cage configuration window and select the Calibration tab, then:

Calibration is performed using a known weight. Each OPAD cage is shipped with a 100g reference weight for this purpose, and if you have this weight then you should use it to perform the calibration. If you don't have the reference weight, then you can use some other weight of an accurately known mass of between 50g and 200g.

In the first step of the calibration, you should specify whether you are using the standard 100g OPAD calibration weight or a weight of some other value. If you are using some other weight, then you should specify how heavy it is. It must be some multiple of 1g between 50g and 200g. After doing this, you should click the Start... button.

In the next step, ANY-maze is going to weigh the empty water bottle, so you should first remove it, empty it, clean it and dry it, then re-install it in the cage and click the Next... button.

ANY-maze will now measure the bottle's weight. It tries to do this as accurately as possible, so it waits for the weight sensor's reading to be very stable, which can take as long as 60 seconds. During this time you should avoid touching the cage or doing anything which may cause it to vibrate. If the reading never stabilizes, then after 60 seconds, you will see a message telling you this and you should try to remove any potential sources of vibration and then retry.

After the system has weighed the empty bottle, you should 'add' the calibration weight to the bottle and weigh it again. The best place to put the weight is on the 'mounting block' that holds the bottle spout - this is shown in figure 2, below. After you have placed the weight, click the Next... button.

Figure 2. Place the calibration weight on top of the bottle mounting block

ANY-maze will then weigh the bottle and the calibration weight. Again, it waits for the weight sensor to be very stable, so again, you should make sure there are no sources of vibration nearby.

After weighing the bottle and calibration weight, the system stores all the calibration data inside the cage itself and the calibration process is complete.

ANY-maze help topic T1206