DC Calibrator Combines Precision Performance with Ease of Operation

The new Yokogawa (the Netherlands) 2553A is a precision DC calibrator combining precision performance and ease of use for the calibration of measuring instruments including analogue meters, thermometers, temperature transmitters and data loggers.

The new unit features high accuracy, high stability, low noise, and high resolution. Intuitive operation is aided by the provision of dials for each digit and switch and a clear display using traditional 7-segment LEDs.

The 2553A is the successor to Yokogawa's earlier 2553 model, but offers higher performance in terms of range and accuracy, additional temperature measurement options, resistance generation, and a choice of communications interfaces as well as being much lighter. The 2553A can be used with existing 2553 programs, allowing its integration in a system containing a mixture of 2553As and 2553s.

The heart of the instrument is a DC current/voltage generator with five voltage ranges from 10 mV to 30 V, four current ranges from 1 mA to 100 mA, ten different types of thermocouple (as specified in IEC standards) as well as Pt100 RTDs (resistive temperature detectors), and a 400-ohm resistance generation range. 

By setting temperature value, the 2553A generates thermocouple electromotive power and can therefore be used to calibrate temperature controllers. It also generates temperature-related resistance values for RTD measurements. Settings can be made by resistance value as well as temperature, making it possible to calibrate using the resistance value.

The 2553A also offers RJC (reference junction compensation) at the output terminals, with a choice of three modes: internal, external and manual.

User defined temperature calibration can be achieved by copying text files including relationship parameters between temperature and voltage or between temperature and resistance, allowing calibration curves to be generated for various types of thermocouple and RTD.

Text files can be easily created by text editor or Excel on a PC. Files can be easily transferred by "drag & drop" operations when the 2553A is connected to a PC via a USB cable, letting the PC recognise the 2553A's internal memory as a mass storage drive.

The 2553A can also be used to calibrate sensor transformers and transmitters for pressure, volume flow and temperature as well as environmental parameters such as pH, ORP (oxidation reduction potential), conductivity or dissolved oxygen. It can also simulate 2-wire transmitters for 4-20 mA signals.

The 2553A measures 132(H) x 213(W) x 300(D) mm, and weighs approximately 3 kg. It comes complete with USB, Ethernet and GP-IB communication interfaces.