Note A - Summary of Significant Accounting Policies (Tables)
|
12 Months Ended |
Sep. 30, 2019 |
|---|
| Notes Tables |
|
| Investments Classified by Contractual Maturity Date [Table Text Block] |
| | | September 30,
2019 | | September 30,
2018 | | Less than one year | | $ | 13,524,270 | | | $ | 8,930,225 | | | 1-5 years | | | 23,902,000 | | | | 17,974,000 | | | Total | | $ | 37,426,270 | | | $ | 26,904,225 | | |
| Financing Receivable, Allowance for Credit Loss [Table Text Block] |
| Year Ended | | Balance at
Beginning
of Year | | Additions
Charged to
Costs and
Expenses | | Less
Write-offs | | Balance
at End
of Year | | September 30, 2019 | | $ | 79,085 | | | $ | 210,000 | | | $ | - | | | $ | 289,085 | | | September 30, 2018 | | | 79,085 | | | | - | | | | - | | | | 79,085 | | | September 30, 2017 | | | 93,473 | | | | - | | | | (14,338 | ) | | | 79,085 | | |
| Schedule of Inventory, Current [Table Text Block] |
| | | September 30,
2019 | | September 30,
2018 | | Raw materials | | $ | 7,115,298 | | | $ | 6,013,166 | | | Work-in-process | | | 540,962 | | | | 560,988 | | | Finished goods | | | 1,356,720 | | | | 3,475,981 | | | Inventories, net | | $ | 9,012,980 | | | $ | 10,050,135 | | |
| Property, Plant and Equipment [Table Text Block] |
| | | September 30,
2019 | | September 30,
2018 | | Manufacturing equipment | | $ | 7,106,041 | | | $ | 5,202,532 | | | Office equipment | | | 3,996,251 | | | | 3,809,614 | | | Leasehold improvements | | | 2,436,346 | | | | 2,417,786 | | | Vehicles | | | 245,903 | | | | 226,221 | | | Construction in progress | | | 8,921 | | | | - | | | Property, plant and equipment, gross | | | 13,793,462 | | | | 11,656,153 | | | Less accumulated depreciation | | | 8,380,221 | | | | 6,911,569 | | | Property, plant and equipment, net | | $ | 5,413,241 | | | $ | 4,744,584 | | |
| Schedule of Finite-Lived Intangible Assets [Table Text Block] |
| | | September 30, 2019 | | | | Years | | Gross Carrying
Amount | | Accumulated
Amortization | | Net Book Value
Amount | | Customer relationships | | | 15 | | | $ | 3,742,000 | | | $ | 405,384 | | | $ | 3,336,616 | | | Certifications | | | 8 | | | | 1,068,000 | | | | 216,937 | | | | 851,063 | | | Trademarks | | | 8 | | | | 563,000 | | | | 114,359 | | | | 448,641 | | | Patents | | | 20 | | | | 530,409 | | | | 38,247 | | | | 492,162 | | | Other | | | 5 | | | | 31,091 | | | | 12,438 | | | | 18,653 | | | Totals | | | | | | $ | 5,934,500 | | | $ | 787,365 | | | $ | 5,147,135 | | | | | September 30, 2018 | | | | Years | | Gross Carrying
Amount | | Accumulated
Amortization | | Net Book Value
Amount | | Customer relationships | | | 15 | | | $ | 3,742,000 | | | $ | 155,917 | | | $ | 3,586,083 | | | Certifications | | | 8 | | | | 1,068,000 | | | | 83,437 | | | | 984,563 | | | Trademarks | | | 8 | | | | 563,000 | | | | 43,984 | | | | 519,016 | | | Patents | | | 20 | | | $ | 393,002 | | | $ | 24,981 | | | $ | 368,021 | | | Other | | | 5 | | | | 31,091 | | | | 6,219 | | | | 24,872 | | | Totals | | | | | | $ | 5,797,093 | | | $ | 314,538 | | | $ | 5,482,555 | | |
| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] |
| Year ended September 30, | | 2019 | | 2018 | | 2017 | | Net income | | $ | 4,566,156 | | | $ | 4,274,547 | | | $ | 3,847,839 | | | Weighted average common shares | | | 13,442,871 | | | | 13,429,232 | | | | 13,532,375 | | | Dilutive potential common shares | | | 8,343 | | | | 23,628 | | | | 128,431 | | | Weighted average dilutive common shares outstanding | | | 13,451,214 | | | | 13,452,860 | | | | 13,660,806 | | | Earnings per share: | | | | | | | | | | | | | | Basic | | $ | 0.34 | | | $ | 0.32 | | | $ | 0.28 | | | Diluted | | $ | 0.34 | | | $ | 0.32 | | | $ | 0.28 | | |
| Useful Lives [Member] |
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| Notes Tables |
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| Property, Plant and Equipment [Table Text Block] |
| | | Years | | Equipment | | | 3 | – | 7 | | Leasehold improvements | | | 7 | - | 10 or life of lease | | Vehicles | | | | 3 | | |