Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Statement of Financial Position [Abstract]
Accounts receivable, allowance for credit loss, current	$ 250	$ 250
Inventory valuation reserves	$ 3,476	$ 3,054
Common stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock issuance (in shares)	12,610,229	11,822,009
Common stock, shares, outstanding (in shares)	12,610,229	11,822,009