Aquaculture electronics components for Norway start with a resistor value that does not exist. We parsed 328,315 distinct Walsin Technology (Walsin) chip and thin film resistor part numbers: none is 250 Ω, the shunt a 4 to 20 mA loop wants, while 360 are 249 Ω, and none of them is on our Hong Kong shelf as at 23 September 2026.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the Walsin chip resistor and thin film exports and a stock list dated 23 September 2026. This post is for a design or sourcing engineer at a Norwegian maker of sensors, controllers or monitoring electronics for fish farms who reads a 4 to 20 mA loop and wants a precision resistor with a second source. Every part number is real and every count is ours. Market statements name their source and the day we read it, 23 October 2026.
How big is Norwegian fish farming, and what changed in 2025?
Bigger, in one year. According to the Norwegian Directorate of Fisheries key figures booklet published on 28 May 2026, Norwegian farmers sold 1,754,557 tonnes of Atlantic salmon and 103,546 tonnes of rainbow trout in 2025, from 995 seawater sites, with 10,354 employees in grow-out and juvenile production.
The same booklet reports 1,202 commercial grow-out licences at 31 December 2025. A SalmonBusiness article dated 13 February 2026 reports that farmed salmon output rose by 200,000 tonnes between 2024 and 2025, the largest annual increase since records began in 1980, and says the 2025 figures were preliminary as of January 2026. Those are the sources’ figures, not ours. We draw one conclusion, and it is ours: a sector that adds 200,000 tonnes of fish in a year, from nearly a thousand sea sites, adds sensors, and every sensor loop has a resistor that somebody has to source. We have no relationship with any Norwegian fish farmer or equipment maker.
Why does a 4 to 20 mA sensor loop need a 250 Ω resistor, and does Walsin list one?
Because 250 Ω turns 4 to 20 mA into 1 to 5 V, and Walsin does not list 250 Ω. Across 75 non-empty resistor files holding 328,315 distinct part numbers, none has a resistance of 250 Ω; the nearest values are 249 Ω (360 parts) and 252 Ω (98 parts). We have not seen this counted anywhere.
If your cage or barge sensors report over a 4 to 20 mA loop, the receiver resistor sets the scale. A 249 Ω part reads 0.996 V at 4 mA and 4.98 V at 20 mA, which is 0.4 percent under the 1 V and 5 V a 250 Ω part gives. Whether 0.4 percent matters is a design decision for you: you can calibrate it out in software, or build 250 Ω from two parts. We counted by opening all 75 files, parsing the resistance field and matching exact values; 23 attenuator rows that hold decibels in the resistance column were left out. Our post on matched thin film pairs for 4 to 20 mA loops covers the pair question, and thin film versus thick film chip resistors explains the families.
Which Walsin parts cross a 250 Ω, 0603, 0.1 percent, 25 ppm brief?
None match on value, and six come close. Of the 360 parts at 249 Ω, 95 are plus or minus 0.1 percent or better, 50 of those state 25 ppm or better, and 43 of those 50 are plus or minus 0.05 percent or better.
The reader’s incumbent goes in the last column.
| Walsin part | Description | On shelf 23 Sep 2026 | Match / mismatch with the brief | Your incumbent |
|---|---|---|---|---|
WF06R2490TTL |
Thin Film Precision WF, 0603, 249 Ω, plus or minus 0.01%, 25 ppm | No | Match on body, tolerance, coefficient; mismatch on value, 249 Ω | |
WF06U2490TTL |
Thin Film Precision WF, 0603, 249 Ω, plus or minus 0.01%, 25 ppm, 1/16 W | No | Match on body, tolerance, coefficient; mismatch on value; lower power than the 1/10 W part above | |
WF04R2490TTL |
Thin Film Precision WF, 0402, 249 Ω, plus or minus 0.01%, 25 ppm | No | Mismatch: value and smaller 0402 body | |
MF12R2490BTL |
Tantalum nitride MF, 1206, 249 Ω, plus or minus 0.1%, 25 ppm | No | Mismatch: value and larger 1206 body | |
WF06K2490BTL |
High Precision Thick Film TC50, 0603, 249 Ω, plus or minus 0.1%, 50 ppm | No | Mismatch: value and 50 ppm coefficient | |
WF06H2490BTL |
High Precision Thick Film TC100, 0603, 249 Ω, plus or minus 0.1%, 100 ppm | No | Mismatch: value and 100 ppm coefficient |
A match in the table is a match on the export fields, no more. Confirm against both datasheets and qualify in your own circuit.
What does the Hong Kong shelf hold at 249 Ω?
Nothing. Of the 360 part numbers at 249 Ω, 0 are on our stock list as at 23 September 2026, so every part in the table is a quote line.
The ready stock list is a dated snapshot, never live-synced, and the chip resistor range lists the families. We hold lot and date-code traceability, a certificate of conformity per shipment on request and original sealed Walsin packaging. Our post on Walsin passive components in Hong Kong stock covers how to read the shelf.
What will we not tell you about marine, safety and compliance?
Anything about how a part behaves at sea. None of the 28 Walsin datasheets we hold mentions fish farming, a marine environment or salt exposure, and the two resistor sheets are for the MR automotive and WR general purpose families, not the thin film parts in this post. We hold no ISO 9001 or IATF 16949 certificate.
We make no claim that any part is qualified for a marine or outdoor installation. We hold no office, entity or stock in Norway; our locations are Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation. We give no legal, customs or conformity advice; confirm with your compliance team. Qualification stays with you.
How can Venatech help a Norwegian aquaculture electronics maker?
How Venatech helps starts with a free paste box. The cross-reference tool decodes 18 manufacturers’ part numbers across 800,000+ crossable parts and shows the Walsin candidates with each field marked match or mismatch. Load a whole BOM, up to 500 part numbers or an Excel or CSV file, to run every line of a sensor interface board. The ready-stock list is a Hong Kong snapshot dated 23 September 2026.
Worked example from our own export: the 250 Ω brief above returned no exact value, 360 parts at 249 Ω and 98 at 252 Ω, and none is stocked. Walsin is the only line we are authorised for; Stackpole and Viking are lines we supply. We serve from Hong Kong in small lots, and you request a quote through the site. We hold 28 Walsin datasheets, 451 pages, and send them on request.
The short version
For a Norwegian aquaculture electronics maker, the 250 Ω loop resistor is a value Walsin does not list: 249 Ω has 360 parts, 50 of them at 0.1 percent and 25 ppm or better, none on our shelf. The cross is quick; the 0.4 percent is yours to decide.
Send us one loop-receiver line from your BOM and we will return the Walsin parts with every difference stated. If your 4 to 20 mA scale assumes 250 Ω exactly, which of your two sources has been checked against it?
Sources
Fetched 23 October 2026.
- Norwegian Directorate of Fisheries, “Key figures from Norwegian aquaculture 2025” (nokkeltall havbruk 2025, English edition), published 28 May 2026: https://www.fiskeridir.no/english/aquaculture/statistics-for-aquaculture/booklets/_/attachment/inline/890c957c-fbef-4a3e-8a7e-d4301089d599:ce284c1041b73547e4e7e0bb90e1537b19ccfe91/nokkeltall-havbruk-2025-eng.pdf
- SalmonBusiness, “Norway’s salmon output jumps by 200,000 tonnes in single year”, 13 February 2026: https://www.salmonbusiness.com/norways-salmon-output-jumps-by-200000-tonnes-in-single-year/
Frequently asked questions
How much salmon did Norway farm in 2025?
According to the Norwegian Directorate of Fisheries booklet published on 28 May 2026, farmers sold 1,754,557 tonnes of Atlantic salmon and 103,546 tonnes of rainbow trout in 2025, from 995 seawater sites. These are the Directorate’s figures, not ours.
Does Walsin list a 250 Ω resistor?
No. None of the 328,315 distinct chip and thin film resistor part numbers in the Walsin exports has a resistance of 250 Ω. The nearest values are 249 Ω, with 360 parts, and 252 Ω, with 98 parts. Confirm against the datasheet.
How much error does 249 Ω add to a 4 to 20 mA loop?
A 249 Ω receiver reads 0.996 V at 4 mA and 4.98 V at 20 mA, which is 0.4 percent under the 1 V and 5 V of a 250 Ω part. Whether that matters, or whether you calibrate it out, is your design decision.
Which Walsin part crosses a 249 Ω, 0603, 0.1 percent, 25 ppm brief?
WF06R2490TTL is a 0603 thin film part at 249 Ω, plus or minus 0.01 percent and 25 ppm, so it matches on body, tolerance and coefficient and differs on value. It is not on the shelf. Confirm against both datasheets and qualify in your own circuit.
Are these Walsin resistors qualified for marine use?
We make no such claim. None of the 28 datasheets we hold mentions fish farming, a marine environment or salt exposure, and we hold no ISO 9001 or IATF 16949 certificate. Qualification for a marine installation stays with you.
Do you hold stock in Norway or give compliance advice?
No. We hold no office, entity or stock in Norway; our locations are Hong Kong, Shenzhen, Singapore and Jiangmen. We give no legal, customs or conformity advice. Confirm with your compliance team. We offer lot and date-code traceability and a certificate of conformity per shipment on request.