Jewellery & precision. 5–10 mg to 600 g.
Eagle Weigh runs jewellery-precision weighing for jewellers, assayers and gold testing labs across India. The J-series card uses the 24-bit ADS1130 (Texas Instruments USA) for the resolution jewellery demands; the LAK-B miniature load cell provides the mechanical precision.
A 200-gram problem.
At a jewellery shop in Karol Bagh on a Saturday afternoon, a buyer brings in a 22-carat necklace for resale. The shopkeeper places it on a precision scale. The display reads 198.46 grams. They settle. Next door, a second shop reads 198.43 on the same necklace. The difference between those two numbers, at today's gold rate, is roughly ₹240. Multiply across a month of trade, and the scale becomes a profit-and-loss line item.
Jewellery weighing is the one place where the 24-bit ADC pays for itself in the first week. The J-series card uses the same Texas Instruments ADS1130 you'd find in a laboratory bench scale — not because the jewellery market demands a laboratory, but because the difference between the right answer and an almost-right answer is real money.
Why jewellery is a different kind of weighing.
Retail weighing is forgiving — a 50 g error on a 5 kg purchase is invisible. Jewellery weighing is unforgiving: a 5 mg drift on a 200 g sample is a measurable financial loss. The 24-bit ADC matters here. The 5-key keypad tuned for jewellery shortcuts matters. The shielded cell-to-board cable matters.
The LAK-B miniature load cell is paired with the J-series card at our calibration bench in Samaypur — each pair travels together, pre-zeroed, pre-checked at three reference points, before it leaves the floor.
The jewellery stack.
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J-series card (J400 / J800)
24-bit ADS1130, jewellery-shop firmware, 5-key UI (sample · piece-count · total · tare · zero).
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LAK-B miniature load cell
Curated from LCT, Zemic (USA) and Green Label. 0.3 kg to 3 kg, IP65 sealing.
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Compact indicator
Table-top metal cabinet with high-bright display. Optional thermal printer for the buyer's slip.
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Pre-calibration
Every cell-and-board pair is calibrated at three reference weights at our bench before dispatch.
What the J-series resolves.
| Spec | Value |
|---|---|
| Resolution | 5 mg / 10 mg / 50 mg — selectable at calibration |
| Top range | Up to 600 g (J800), 300 g (J400) |
| ADC | 24-bit ADS1130 (Texas Instruments, USA) |
| UI | 5-key tuned for jewellery: sample · piece-count · total · tare · zero |
| Sealing | Cell IP65 · indicator cabinet metal-shielded |
| Drift | Auto-zero on cold-start; cal-lock on inspector seal |
| Warranty | 1 year + same-day phone support |
Where the J-series ships.
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Jewellery retail counters
Standalone shops weighing 5–10 g earrings up to 200 g chains. J800 + tabletop indicator.
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Gold assayers
Workshops testing purity by weight-loss after acid bath. J400 for the fine work.
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Bullion dealers
Higher capacity (up to 600 g) for bullion bar weighing with audit-trail slips.
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Hallmarking centres
Centres that need cal-lock + inspector seal for compliance with BIS hallmarking protocols.
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Pawnbrokers
Quick-turnover counters that need a clear slip the customer can dispute against.
FAQ for jewellery buyers.
How precise is the J800?
5 mg readability across the top range when calibrated and zero-stabilised. The 24-bit ADC reports 100,000+ internal divisions; we present them to the user as a 5/10/50-mg step depending on the application.
Does it handle air-current drift in a busy shop?
Yes. Auto-zero on idle, air-lock filter on the firmware, and the indicator cabinet is metal-shielded. We recommend a wind-shield enclosure on the cell for shops with ceiling fans directly above the counter.
Can I verify the scale against a reference weight?
Yes — the J-series ships with a calibration mode that walks the operator through a known-weight check (you supply the reference weight to BIS class).
How is the cell paired to the board?
At our Samaypur bench. Every shipped pair is checked at three reference points before the cable is tied. This is why we don't sell J-series cells separately from the board.
Do you certify for hallmarking-centre use?
Eagle Weigh hardware is BIS-class compliant; certification is centre-by-centre — talk to our sales desk with your hallmarking-centre requirements.
Specifying a jewellery scale?
Tell us the resolution you need (5, 10 or 50 mg) and the slip format. We'll match the J-series card to the right LAK-B cell and ship pre-calibrated.