A portable air blower is selectively removably secured to the upper end of a length adjustable extension pole to blow twigs, leaves or other debris from a rain gutter or other elevated structures or surfaces. The compounds act as diuretics and natriuretics and are valuable pharmaceutically active compounds for the therapy and prophylaxis of medical conditions including cardiovascular diseases such as hypertension and conditions resulting from excessive salt and water retention. Each time a history readout switch is depressed, a channel history is read out from the history table. The test environment may provide visual representations of the test steps in the sequence of test steps.