Heat Seal Tester Models: Compare STH-3, STH-3A, and STH-5
All three KHT STH heat seal testers comply with ASTM F88 and F2029. The right model depends on your testing volume, temperature gradient needs, data logging requirements, and budget. Side-by-side comparison below.
Budget FriendlySTH-3
Manual Entry-Level
Straightforward manual heat seal tester for labs that need ASTM F88/F2029 compliance at lowest cost.
Temp Range
0–300°C
Accuracy
±0.5°C
Force
0–600N
Positions
1
Most PopularSTH-3A
Digital 5-Position Gradient
Flagship digital gradient model. Test 5 temperatures simultaneously — map your full seal window in one 30-minute run.
Temp Range
0–300°C
Accuracy
±0.5°C
Gradient
5-position
Display
Digital LED
Production ReadySTH-5
Touchscreen IoT
Touchscreen IoT model with programmable profiles, auto data logging, and USB/LAN export for production environments.
Interface
7" Touchscreen
Accuracy
±0.5°C
Export
USB/LAN
Profiles
Programmable
Model Comparison
STH-3 vs STH-3A vs STH-5: Choose Your Model
All three models comply with ASTM F88 and F2029. The right choice depends on your testing volume, required data output, and IoT integration needs.
| Feature | STH-3 (Manual) | STH-3A (Gradient) | STH-5 (Touchscreen) |
|---|---|---|---|
| Temperature Range | 0–300°C | 0–300°C | 0–300°C |
| Temp Accuracy | ±0.5°C | ±0.5°C | ±0.5°C |
| Sealing Force | 0–600N | 0–600N | 0–600N |
| Test Positions | 1 | 5 (gradient) | 1 (programmable) |
| Control Type | Manual dial | Digital LED | 7" Touchscreen |
| Data Logging | Manual record | Manual record | Auto USB/LAN |
| IoT / Remote | No | No | Yes |
| Best For | Small R&D labs | Film R&D / QC | Production pharma/battery |
| ASTM F88 | ✓ | ✓ | ✓ |
| ASTM F2029 | ✓ | ✓ | ✓ |
| ISO 11607 | — | Compatible | ✓ |
Frequently Asked Questions
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