Every handheld lamp eventually meets a joint it cannot cure the same way twice. Recognizing that moment, and knowing what a lightguide-based spot lamp changes, saves rework and failed bond checks.
Q: When Should I Replace a Handheld UV Lamp With a Spot Lamp?
A: When Repeatability, Reach, or Intensity Becomes the Constraint
Move to a spot lamp when the process needs a repeatable, documented dose at a small bond point, when the joint sits somewhere a lamp body cannot reach, or when intensity per area must exceed what a portable unit holds. Incure’s LED option is the L9000™ UV LED spot lamp; the broad-spectrum alternative is the S20™ arc spot lamp.
Five Signs You Have Outgrown the Handheld
- Cure results vary between operators. Distance, angle, and dwell time all depend on a hand.
- The bond line is recessed. A lamp head is bulky; a lightguide tip is not.
- Parts need a timed, logged exposure for quality records.
- Several joints per part make sequential curing the bottleneck.
- The adhesive demands more irradiance than the portable lamp can deliver at a usable distance.
One sign is a nuisance; two or more justify the change.
What the Lightguide Changes
A spot lamp separates the light source from the bond point. The lamp stays on the bench, and a flexible lightguide carries output to the joint. The L9000™ is offered with three guide lengths: a 24 mm cube head with fan (Cool Guide, 83 mm total length), a 66 mm fiber optic guide (Short Guide), and a 118 mm guide (Long Guide) for deep fixtures. Up to four lightguides can run from one controller, so a multi-point part does not need a second lamp. The S20™ uses 1-, 2-, 3-, or 4-pole liquid lightguides in a similar logic, splitting output across several cure points.
Intensity Per Area
A handheld spreads limited power across a broad beam. A spot lamp concentrates it. At a 9 mm focal point the L9000™ reaches 7,500 mW/cm² at 365 nm, with spot diameter ranging from 3 mm to 12 mm across its 9–30 mm focal range. Concentrated irradiance cures thick or filled materials in less time, and the fixed focal geometry keeps that number stable. For comparison, an area flood lamp such as the L44 reads 3,100 mW/cm² over a 4″ square; the spot lamp trades area for intensity.
Repeatability Through Control
The L9000™ provides a programmable 0.1–999.9 second timer and 10–100% adjustable intensity, and an RS-232 port supports PLC-triggered activation. The S20™ offers a programmable 1–99 second timer and 25–100% adjustable intensity, with constant power regulation. Those controls replace operator judgment with set values, so the dose reaching the bond line is the same every cycle.
Email Us with your joint depth, spot size, and adhesive wavelength, and Incure’s engineers can match a lightguide and lamp to the fixture.
Choosing LED or Arc for the Upgrade
- LED spot (L9000™): instant full intensity, no warm-up, single wavelength per unit chosen from 365, 375, 385, 395, or 405 nm. Suits a validated, single-chemistry process.
- Arc spot (S20™): 275–650 nm broad spectrum from a 200W mercury arc, needing 1–2 minutes to reach full output. Suits labs that cure several chemistries.
A lab running mixed materials often prefers the arc’s breadth; a production station with one adhesive usually prefers LED consistency.
Fixturing and Verification
A spot lamp is only repeatable if the guide tip is fixed. Use a bracket that holds the working distance, because irradiance falls steeply with distance. Then measure at the actual position with a radiometer and record the dose. That measurement-first habit is what separates a controlled process from a hopeful one.
A Worked Comparison
Consider a three-joint electronics subassembly where each joint sits 20 mm below a housing edge. A handheld lamp must be repositioned three times, and the operator cannot see the joint while exposing it. A spot lamp with a long lightguide reaches all three in one setup: the guide tips are clamped once, the controller fires a single timed exposure, and the cure step stops being the slowest operation on the station. The saving shows up as fewer touch-ups, because every joint receives the same dose.
Transition Checklist
Before changing equipment, list the adhesive’s cure wavelength, the smallest joint diameter, the deepest recess, and the cycle time target. Those four numbers decide the lightguide length, spot size, and lamp type in almost every case, and they make a quote request from the supplier far more precise.
Final Thoughts
A handheld lamp serves the bench; a spot lamp serves the process. When variation between operators, recessed joints, or multi-point parts start costing rework, the lightguide-based upgrade pays for itself in consistency. Contact Our Team to plan the transition from a portable lamp to a fixtured spot-curing station.
Visit www.incurelab.com for more information.