MKN TES-1364/1365 Portable Temperature and Humidity Meter with RS-232 Interface

Overview

The MKN TES-1364/1365 is a handheld, dual-parameter environmental meter engineered for reliable, real-time monitoring of ambient temperature and relative humidity in laboratory, industrial, HVAC, and quality assurance settings. Based on precision thermistor and capacitive polymer sensing technology, the instrument delivers stable, repeatable measurements across its full operational range. The TES-1365 variant extends functionality with integrated psychrometric calculations—including dew point and wet-bulb temperature—enabling users to assess condensation risk and thermal comfort parameters without external computation. Its retractable probe design facilitates access to confined or hard-to-reach locations while maintaining sensor integrity during transport and storage. The device complies with IEC 61000-4 electromagnetic compatibility standards and meets general requirements for portable electronic measuring instruments per IEC 61010-1 regarding safety in measurement applications.

Key Features

• Dual-line LCD display with analog-style bar graph for intuitive trend visualization—simultaneously shows temperature (°C/°F) and relative humidity (%RH)
• High-resolution readout: 0.1 °C/0.1 °F/0.1% RH resolution supports fine-grained environmental tracking
• Data hold and relative value comparison mode for baseline-referenced measurements
• TES-1365-specific capabilities: scheduled auto-power activation/shutdown, timestamped min/max logging, and onboard dew point/wet-bulb computation
• Robust data management: 15,000 continuous memory slots plus 99 manual entries; all accessible via front-panel interface or PC export
• RS-232 serial interface (TES-1365 only) with included Windows-compatible software for time-synchronized data download, graphical analysis, and CSV export
• Input protection circuitry rated for up to 60 V DC or 24 V_RMS AC, safeguarding against accidental overvoltage exposure
• Ergonomic housing with protective rubberized grip and optional carrying case for field durability

Sample Compatibility & Compliance

The TES-1364/1365 is designed for non-invasive ambient air monitoring only and is not intended for immersion, corrosive gas exposure, or high-velocity airflow without optional protective shielding. It operates within standard atmospheric pressure conditions (86–106 kPa) and exhibits minimal drift under steady-state environments per ISO 7726 Annex B guidelines for thermal environment instrumentation. While not certified to GLP or GMP validation protocols out-of-the-box, its traceable accuracy specifications (±0.5 °C, ±3% RH in mid-range) align with routine environmental verification requirements in pharmaceutical stability chambers (ICH Q1A), cleanroom monitoring (ISO 14644-3), and warehouse qualification (WHO Technical Report Series No. 992). Calibration certificates are available upon request and may be issued with NIST-traceable references.

Software & Data Management

The bundled PC application (Windows 7–11 compatible) provides secure, timestamped data retrieval from the TES-1365’s internal memory via RS-232 connection. Users can configure logging intervals, annotate sessions, generate annotated time-series plots, and export datasets in comma-separated values (CSV) format for integration into LIMS or statistical process control platforms. Audit trail functionality includes operator ID input, session start/end timestamps, and automatic firmware version logging—supporting basic 21 CFR Part 11 compliance when deployed with organizational procedural controls. No cloud synchronization or remote access features are implemented; all data remains local unless explicitly exported by the user.

Applications

• Environmental validation of storage areas for temperature-sensitive pharmaceuticals and medical devices
• Baseline characterization and periodic monitoring of HVAC performance in laboratories and production facilities
• Field verification of climate-controlled transport containers (e.g., cold chain logistics audits)
• Educational demonstrations of psychrometric relationships and heat-moisture transfer principles
• Preventive maintenance support for dehumidification systems through long-term RH trend analysis
• Documentation of ambient conditions during equipment calibration or metrology lab accreditation assessments

FAQ

Does the TES-1364 support RS-232 communication?

No—only the TES-1365 model includes an RS-232 port and associated PC software.
Can the device measure dew point directly without calculation?

It does not include a dedicated dew point sensor; dew point is derived algorithmically from measured temperature and RH using the Magnus formula per ISO 4677-2.
Is battery replacement possible in the field?

Yes—the six AAA cells are user-replaceable without tools, and low-battery indication appears on the LCD prior to shutdown.
What is the recommended recalibration interval?

MKN recommends annual verification against a reference hygrometer and dry-well calibrator, especially if used in regulated environments or after mechanical shock.
Does the unit meet IP rating requirements for dust or moisture resistance?

It carries no formal IP rating; operation is limited to indoor, non-condensing environments per its specified 10–95% RH operating range.