CMK-02 Volume Corrector

COMMON S.A. | Gas Measurement Systems | View PDF

The microcomputer CMK-02 Volume Corrector is supplied either form batteries or from mains, and may be used in gas measuring systems where high measurement accuracy , reliability and servicing simplicity is required at competitive price.

The features of the CMK-02 corrector, including the possibility of extending with additional measurements, enable to apply the device in measuring systems where, till now, it was necessary to use much more expensive flow computers. The device complies with domestic and European Union standards.

The CMK-02 Volume Corrector is the device oparating in 3V technology, made with the use of double side surface mounting (SMT).

CHARACTERISTIC FEATURES

Possibility of monitoring the instanteous gas flow by means of signals from the high or low frequency transmitters (HF and LF) of gas meters provided with pulse transmitters (i.e. turbine or rotary ones)
Access to the terminal strips and replacement of batterieswithout opening the electronic container
Four line LCD display thet maintains contrast in the whole range of permissible ambient temperature and simple intuitive operation of the corrector with the help of four keys assures easy communication with the corrector.
Daily data memory for the period of last 5 years.
Two digital inputs and two digital outputs with programmed function (e.g. alarm protecting against exceeding of the ordered power)
Two independent serial transmission channel
One cable for supplying and data transmission, consistent with RS-GAZ2
Multilevel data access protection system.
Minimun 5 years operating period without battery replacement, confirmed in exploitation.
Calculation algorithms of volume correction for natural gas, propane-butane, nitrogen, air, carbon dioxide, etc.

BASIC FUNCTIONS

Conversion of the real gas volume, measured by the gas meter, to the volume at base conditions (p=101,325kPa, T=273,15K; in some countries this may vary) that is the ground for clearing accounts with the gas supplier. The volume corrector performs calculation based on the number of LF pulses of the gas meter that measures the gas volume at operating conditions, as well as based on measurements of the gas temperature and pressure. The compressibility coefficient is calculated either by the SGERG 88 or AGA NX19 methods.

COMMUNICATION

Two serial output ports, operating independently, give possibility to monitor simultaneously the gas flow and read the data (also by the modem). Reading the data from the corrector is performed with the help of MAC (DOS) or GMWIN (Windows) software. It is possible to program the corrector with the help of the keypad or service software. The programming functions executed with the help of the keypad are activated by the microswitch accessible after taking off the seal and opening battery compartment casing.All services actions are written down in the volume corrector’s memory together with the service engineer’s ID code.