Note 5 - Business Acquisitions (Details Textual)									3 Months Ended				6 Months Ended	7 Months Ended	9 Months Ended
		Sep. 28, 2022 USD ($)	Sep. 28, 2022 EUR (€)	Sep. 27, 2022 USD ($)	May 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($)	Aug. 31, 2021 USD ($) shares	Apr. 29, 2021 USD ($)	Dec. 24, 2022 USD ($)	Dec. 24, 2022 USD ($)	Dec. 24, 2022 USD ($)	Dec. 25, 2021 USD ($)	Dec. 24, 2022 USD ($)	Dec. 24, 2022 USD ($)	Dec. 24, 2022 USD ($)	Dec. 25, 2021 USD ($)
Revenues, Total	[1]									$ 57,402,000		$ 50,902,000			$ 168,502,000	$ 149,079,000
Operating Income (Loss), Total										$ 3,163,000		$ 2,361,000			10,393,000	9,628,000
General and Administrative Expense [Member]
Business Combination, Acquisition Related Costs															100,000	900,000
Complete Calibrations [Member]
Revenues, Total									$ 100,000
Operating Income (Loss), Total									$ 100,000
e2b [Member]
Revenues, Total											$ 900,000
Operating Income (Loss), Total											$ 200,000
Alliance [Member]
Revenues, Total														$ 1,300,000
Operating Income (Loss), Total														$ 100,000
Tangent [Member]
Revenues, Total															1,700,000
Operating Income (Loss), Total															100,000
Complete Calibrations [Member]
Payments to Acquire Businesses, Gross		$ 1,200,000
Complete Calibrations [Member] | Technology License Agreement [Member]
Royalties Per Technology Calibration		$ 3	€ 3
Technology License Agreement, Term (Year)		10 years	10 years
Cumulative License Revenue		$ 800,000	€ 750,000
Annual Royalty Fee, Amount		$ 100,000	€ 100,000
e2b [Member]
Payments to Acquire Businesses, Gross				$ 3,100,000
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life (Year)				15 years
Business Combination, Consideration Held Back				$ 900,000
Alliance [Member]
Payments to Acquire Businesses, Gross					$ 4,000,000.0
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life (Year)					15 years
Business Combination, Consideration Held Back					$ 500,000
Business Combination, Consideration Transferred, Total					$ 4,700,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares					2,284
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable					$ 100,000
Business Combination, Consideration Subject to Reduction					$ 500,000
Tangent [Member]
Payments to Acquire Businesses, Gross						$ 7,900,000
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life (Year)						15 years
Business Combination, Consideration Transferred, Total						$ 8,900,000
Escrow Deposit						$ 1,000,000.0
Cash Out of Escrow Account													$ 200,000
NEXA [Member]
Payments to Acquire Businesses, Gross							$ 23,900,000
Revenues, Total															9,800,000
Operating Income (Loss), Total															200,000
Acquired Finite-Lived Intangible Assets, Weighted Average Useful Life (Year)							5 years
Business Combination, Consideration Transferred, Total							$ 26,200,000
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares) | shares							34,943
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable							$ 2,400,000
Escrow Deposit							100,000
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High							$ 7,500,000
Business Combination, Contingent Consideration Arrangements, Period (Year)							4 years
Business Combination, Contingent Consideration, Liability, Total							$ 200,000
NEXA [Member] | Measurement Input, Cost to Sell [Member]
Business Combination, Contingent Consideration, Liability, Measurement Input							0.0660
NEXA [Member] | Measurement Input, Risk Free Interest Rate [Member]
Business Combination, Contingent Consideration, Liability, Measurement Input							0.0058
NEXA [Member] | Measurement Input, Price Volatility [Member]
Business Combination, Contingent Consideration, Liability, Measurement Input							0.2000
Upstate Metrology [Member]
Business Combination, Consideration Transferred, Total								$ 900,000
Payment for Contingent Consideration Liability, Financing Activities															$ 0	$ 0

[1] Revenues are attributed to the countries based on the destination of a product shipment or the location where service is rendered.