Disclosed and claimed herein are novel thallium-sensitive assays for identifying modulators of ion channels, channel-linked receptors or ion transporters. Upon judging the slave device to have been switched off, the master device turns off its own power supply in synchronism with the deactivated slave device. Power consumption can be reduced in controlling exposure using the electronic shutter. In use, information is spread when people share data with non-users. The metal member and the lid enclose substantially the semiconductor device for providing electromagnetic interference shielding. The machine specification are used to identify salient observations that can be derived from measurement data regarding the machine performance.