INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Components of income tax expense
Effective corporate tax rate	21.00%	34.00%
Tax impact due to U.S.Tax reform	$ 223
Current taxes - Federal	(38)	$ (124)
Current taxes - State	10	10
Current taxes - Foreign	334	49
Deferred taxes - Federal		176
Deferred taxes - State		239
Deferred taxes - Foreign	20	25
Income tax expense	326	375
Reconciliation of federal income taxes and reported income taxes
Statutory federal tax provision (benefit)	107	(704)
State income tax benefit	(36)	(117)
Effect of foreign operations	52	(88)
Uncertain tax positions	(19)
Income tax credits		(112)
Valuation allowance	(199)	1,011
Permanent differences	15	8
Global Intangible Low-Taxed Income Effect	296
Return to Provision - Credits and NOL	176
Deferred adjustments	(62)
Loss of Section 199 due to carryback claim		46
Effects of tax reform		280
Other	(4)	51
Income tax expense	326	375
Income (loss) from operations before income taxes
Domestic	(1,090)	(2,831)
Foreign	1,582	760
Income (Loss) before income taxes	492	(2,071)
Components of deferred tax assets (liabilities)
Allowance for uncollectable accounts	53	49
Inventories reserve	267	198
Accrued vacation	145	194
Amortization		191
Stock-based compensation and equity appreciation rights	54	23
Net operating loss carryforwards	175	359
Tax credit carryforwards	449	613
Other	76	24
Deferred tax assets before valuation allowance	1,219	1,651
Valuation allowance	(614)	(1,146)
Deferred tax assets	605	505
Prepaid expenses	(40)	(165)
Section 481(a) adjustment	(249)
Property and equipment	(316)	(319)
Deferred tax liabilities	(605)	(484)
Net deferred tax assets		21
Valuation allowance on foreign assets	0
Changes in total gross unrecognized tax benefit liabilities, excluding accrued interest
Balance at the beginning of the year	52	52
Additions based on tax positions related to the current year		22
Statute of limitations	(19)	(22)
Balance at the end of the year	33	$ 52
Federal
Operating loss carryforwards
Net operating loss carryforwards	23
Federal | General business
Tax credit carryforwards
Tax credit carryforwards	284
Minnesota | State
Operating loss carryforwards
Net operating loss carryforwards	1,168
Minnesota | State | R&D
Tax credit carryforwards
Tax credit carryforwards	198
Iowa | State
Operating loss carryforwards
Net operating loss carryforwards	400
Montana | State
Operating loss carryforwards
Net operating loss carryforwards	4
Wisconsin | State
Operating loss carryforwards
Net operating loss carryforwards	$ 662