1. Overview

The PR550 Series Portable Liquid Calibration Baths while nearly identical in the compact size and weight to conventional dry block calibrators, combine the advantages of liquid thermostatic bath - such as superior uniformity, large heat capacity, and exceptional resistance to environmental interference, with excellent static and dynamic temperature control characteristics. PR552B/PR553B models feature integrated full-function temperature measurement channels and standard instrument measurement channels, supporting editable calibration tasks. This enables fully automated on-site calibration of thermocouples, RTDs, temperature switches, and electrical-output temperature transmitters without external devices.

Traditional on-site calibration process usually uses the dry block calibrators as the temperature sources. The dry blocks calibrator biggest advantage is its small size and portability. However, its temperature uniformity is completely dependent on the heat conduction between the metal material and the air. This not only places high demands on the diameter matching between sensors and jacks but also fails to compensate for calibration errors caused by external thermal conduction of sensors with different specifications, often leading to less-than ideal calibration results.

1.1 Appearance

PR550B Series Products Appearance

PR550C Series Products Appearance

1.2 Technical Features

• Excellent heating/cooling and constant temperature characteristics: Faster heating/cooling rates and shorter stabilization time are crucial for efficient on-site calibrations. The PR550 series portable calibration baths adopt innovative technologies including dual-zone heaters, AC/DC hybrid temperature control, and variable-speed stirring to enhance the dynamic and steady-state control performance of compact liquid constant temperature sources. Taking PR553B/C as an example: it only takes 12 minutes to heat up from ambient temperature to 100°C and reach stability, enabling fully automatic calibration of 3-4 temperature points within 1 hour - significantly improving on-site calibration efficiency.

• Compact and easy to carry, the entire product series incorporates multiple lightweight designs while ensuring structural strength meets requirements. Its compact dimensions and curb weight make it exceptionally easy to deploy at work sites. Taking the PR553B/C as an example, its total weight when filled with medium is merely 12kg, comparable to conventional dry block calibrators.

• Sealed design prevents medium spillage during routine transit. The entire product series is equipped with dedicated flanges and sealing covers for the working cavity, along with a two-stage high-temperature resistant sealed bearing for the stirring motor's rotating shaft at the rear. This effectively prevents medium spillage under all circumstances except when dumping or inversion.

• The PR552B/PR553B has independent dual-channel measurement function. The first channel offers full-function measurement capacity, connecting to calibrated targets such as RTDs, thermocouples, temperature transmitters, and temperature switches via the terminal block on the left side of the screen. It also integrates a built-in 24V power supply. The second channel is used to connecting the standard reference temperature sensor, which employs a wire-wound platinum RTD to ensure superior long-term stability and dynamic response characteristics.

• The PR552B/PR553B has both temperature control mode and task mode, which can be switched with one button. In temperature control mode, users can view all real-time parameters related to temperature control, such as control curves and stability fluctuation. Task mode is designed for fully automatic calibration across multiple temperature points, allowing users to set key process parameters including calibrated target type, calibration temperature points, heating/cooling rates, Ramping directions (up/down), and stability judgment criteria. Real-time data can be monitored during automatic calibration, and calibration results are generated upon task completion. The PR552C/PR553C only support temperature control mode.

1.3 Main Function List

Note: Features marked in blue are exclusive to PR552B/PR553B models.

1.4 Operational Interfaces (PR552B/PR553B)

2.  Technical Parameters

2.1  General Technical Parameters

2.2  Temperature Technical Parameters

2.3  Electrical Measurement Technical Parameters

2.4  Thermocouple Measurement Parameters

2.5  RTDs Measurement Parameters

3. Packaging Information

3.1 Packaging List