testo 826-T4 Infrared & Immersion Thermometer
| Brand | testo |
|---|---|
| Origin | Germany |
| Model | testo 826-T4 |
| Instrument Type | Portable |
| Optical Resolution | 6:1 |
| Laser Targeting | Single-point |
| IR Temperature Range | −50 to +300 °C |
| IR Accuracy | ±1.5 °C (−20 to +100 °C), ±2 °C or ±2 % of reading (remaining range) |
| NTC Probe Range | −50 to +230 °C |
| NTC Accuracy | ±0.5 °C (−20 to +99.9 °C), ±1 °C or ±1 % of reading (remaining range) |
| IR Measurement Speed | 0.5 s |
| NTC Measurement Speed | 1.25 s |
| Resolution | 0.1 °C (both modes) |
| Display | Single-line LCD |
| IP Rating | IP67 (with protective sleeve) |
| Weight | 80 g |
| Dimensions | 148 × 34.4 × 19 mm |
| Operating Temperature | −20 to +50 °C |
| Storage Temperature | −40 to +70 °C |
| Power Supply | 2 × AAA batteries |
| Battery Life | Approx. 20 h |
| Compliance | EN 13485, HACCP-ready |
Overview
The testo 826-T4 is a dual-mode portable thermometer engineered for rigorous temperature verification in food safety-critical environments. It integrates non-contact infrared (IR) surface thermometry with direct-contact immersion measurement via an integrated NTC probe — enabling rapid, traceable, and legally defensible temperature assessment at multiple physical points on a single instrument. Its measurement principle relies on calibrated IR radiation detection (based on Planck’s law) for surface readings and high-stability NTC thermistor response for core temperature penetration. Designed specifically for HACCP-aligned workflows, the device supports real-time decision-making during goods receipt, cold chain monitoring, production line checks, and post-process validation — all while maintaining full compliance with EN 13485 requirements for medical device-related quality management systems and widely adopted food safety protocols.
Key Features
- Dual-sensor architecture: Simultaneous IR surface scanning (−50 to +300 °C) and NTC immersion measurement (−50 to +230 °C) in one compact unit
- Single-point laser targeting with 6:1 optical resolution — optimized for reliable mid-distance measurements on typical food packaging and product surfaces
- User-definable dual alarm thresholds with audible and visual alerts — configurable for both IR and probe modes independently
- Max/min value tracking and hold function — automatically records and displays extremal values from the most recent measurement sequence
- IP67-rated protective sleeve included — fully submersible, dishwasher-safe, and designed for repeated sanitation in hygienic environments
- Built-in accessories: Freeze-core drill bit for frozen food penetration, mounting bracket, probe protection cap, and pre-installed AAA batteries
Sample Compatibility & Compliance
The testo 826-T4 is validated for use across diverse food matrices including dairy products (e.g., yogurt, cheese), raw and cooked meats, chilled ready-to-eat meals, and frozen commodities. Its 55 mm stainless-steel probe sleeve ensures safe, consistent insertion depth without cross-contamination risk. The device meets EN 13485:2016 for quality management system applicability in regulated sectors and supports documented HACCP implementation through auditable measurement records. While not intrinsically 21 CFR Part 11 compliant (as it lacks electronic signature capability), its measurement repeatability, calibration traceability (via optional testo calibration certificate), and alarm logging functionality align with GLP/GMP documentation expectations for routine QC checks.
Software & Data Management
The testo 826-T4 operates as a standalone field instrument with no onboard data logging or Bluetooth connectivity. All measurements are displayed in real time on its single-line LCD screen; values are not stored internally. For audit readiness, users are expected to manually record results alongside timestamps and sample identifiers in external logbooks or LIMS-integrated forms. Optional testo calibration services provide ISO/IEC 17025-accredited certificates, ensuring metrological traceability to national standards. The device’s design prioritizes operational simplicity over digital integration — making it suitable for frontline staff requiring immediate, unambiguous pass/fail decisions without software dependencies.
Applications
- Goods receipt inspection: Rapid verification of incoming refrigerated/frozen shipments against critical control points (CCPs)
- Production line monitoring: Spot-checking core temperatures during thermal processing, chilling, or freezing stages
- Storage validation: Periodic temperature mapping of cold rooms, blast chillers, and display cabinets
- Catering and retail: On-site compliance checks for hot-holding units, salad bars, and deli counters
- Training and internal audits: Demonstrating procedural adherence to HACCP plans during staff competency assessments
FAQ
Does the testo 826-T4 support data export or PC connectivity?
No — it is a dedicated handheld instrument without memory storage, USB, or wireless interfaces.
Can the IR sensor be recalibrated in the field?
No — factory calibration is performed during manufacturing; periodic verification using certified reference sources (e.g., blackbody calibrators) is recommended per ISO/IEC 17025 guidelines.
Is the probe suitable for measuring liquid or semi-solid foods?
Yes — the 55 mm probe sleeve enables stable immersion in viscous or particulate-laden media such as sauces, soups, and soft cheeses.
What is the typical battery life under continuous use?
Approximately 20 hours with two AAA alkaline cells; low-battery indicator appears before shutdown.
How does the 6:1 optical resolution affect measurement accuracy at distance?
At 60 cm distance, the IR spot size is ~10 cm diameter; users must ensure target area fully fills the spot to avoid background radiation interference.
