JOFRA ETC Series Portable Dry-Block Temperature Calibrator

Overview

The JOFRA ETC Series Portable Dry-Block Temperature Calibrator is a compact, high-response thermal calibration instrument engineered for rapid, reliable temperature verification of contact sensors—including RTDs, thermocouples, and thermistors—in both field and laboratory environments. Operating on the principle of conductive heat transfer through a precisely machined metal block (typically aluminum or brass), the ETC series eliminates reliance on liquid baths or oil media, offering immediate thermal response and minimal maintenance. Its design prioritizes operational efficiency: achieving full thermal equilibrium in under three minutes across its full operating range (–10°C to 400°C) enables technicians to perform multiple calibrations per hour without compromising repeatability. The unit’s robust mechanical architecture—featuring corrosion-resistant stainless steel housing and impact-dampening rubber side panels—is validated for sustained use in industrial settings, including manufacturing floors, power plants, and HVAC service vehicles.

Key Features

• Rapid thermal response: Heats at up to 100°C per minute; reaches thermal stability in ≤3 minutes across the entire range
• High short-term stability: Maintains ±0.05°C over 10-minute intervals, critical for sensor drift assessment and multi-point calibration routines
• Field-optimized ergonomics: Compact footprint and low mass enable placement in confined spaces; weighs under 4.5 kg for unrestricted portability
• Intuitive operator interface: Backlit LCD display shows setpoint, actual block temperature, stability status, and customizable countdown timer
• Precision control: 0.1°C temperature resolution with digital PID algorithm ensuring minimal overshoot and consistent ramp profiles
• Dual-zone capability (on select ETC variants): Independent control of upper and lower block zones supports simultaneous calibration of multi-sensor assemblies

Sample Compatibility & Compliance

The ETC Series accommodates standard probe diameters from 3 mm to 25 mm via interchangeable well inserts (sold separately), supporting common industrial sensor formats such as 1/4″, 3/8″, and 1/2″ sheathed elements. Calibration procedures align with international standards including ASTM E74-22 (Standard Practice for Calibration of Laboratory Thermometers), ISO 17025:2017 (General Requirements for the Competence of Testing and Calibration Laboratories), and IEC 60584-1 (Thermocouples — Part 1: EMF Specifications). While not intrinsically rated for hazardous areas, the unit meets CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). Traceability documentation—including factory calibration certificates with NIST-traceable references—is available upon request to support GLP/GMP audit readiness.

Software & Data Management

The ETC Series operates autonomously without mandatory PC connectivity; however, optional JOFRA ComSoft™ v5 software enables automated calibration sequence execution, data logging, and report generation compliant with FDA 21 CFR Part 11 requirements—including electronic signatures, audit trails, and user access controls. Raw temperature data (setpoint, measured block temp, stability flag, timestamp) is exportable in CSV or XML format for integration into LIMS or enterprise quality management systems. All internal firmware updates are performed via USB flash drive, eliminating dependency on proprietary cables or drivers.

Applications

• On-site verification of temperature transmitters and controllers prior to commissioning or after maintenance
• Routine calibration of handheld thermometers and portable data loggers in pharmaceutical cleanrooms and food processing lines
• Validation of oven, furnace, and autoclave sensor arrays during PQ/UQ protocols
• Technical training labs where rapid setup, safety, and intuitive operation are essential pedagogical requirements
• Third-party calibration service providers requiring transportable assets with documented metrological performance

FAQ

What is the recommended warm-up time before initiating a calibration sequence?
A minimum of 15 minutes is advised after power-on to allow internal electronics and thermal mass to reach ambient equilibrium; however, the block itself achieves target stability in ≤3 minutes once heating begins.
Can the ETC calibrate thermocouples directly without a reference thermometer?
No—the ETC provides a stable thermal environment but does not measure sensor output. A calibrated reference thermometer (e.g., PRT or certified thermocouple) and appropriate readout device are required for comparison-based calibration.
Is external cooling required to accelerate cooldown below 100°C?
Natural air convection is sufficient for most applications; forced-air cooling accessories are available as optional add-ons for users requiring sub-60-second cooldown from 400°C to 50°C.
Does the ETC Series support custom calibration tables for non-standard thermocouple types?
Yes—ComSoft™ allows import of user-defined ITS-90 or polynomial coefficients for exotic alloys (e.g., Type C, W-Re) and legacy sensor specifications.
How often should the ETC be recalibrated to maintain stated accuracy?
Annual recalibration against traceable standards is recommended; more frequent verification (e.g., daily or per-shift) using a certified reference probe is advised in regulated environments.