The CalorVal BTU Analyzer

The CalorVal analyzer model SNR690 is an industrial strength assembly consisting of a heated flame cell and integrated controller that continuously measures calorific values from 0 to 1300/2500 BTU/ft3 of gaseous streams of industrial processes.

The sample is drawn into the flame cell and mixed with Hydrogen fuel before introduction to the burner. Directly above the burner is a thermocouple used to sense the heat produced by the burning gases and vapors. A temperature detector converts this temperature rise into an electrical signal that is proportional to the concentration of gas.

The analyzer displays a uniform response to a wide range of combustible gases. These close response factors allow accurate measurements of gas mixtures with variable compositions.

To avoid condensation during sampling, the entire analyzer pneumatic assembly is heated up to 120°C. This eliminates both inaccurate readings as well as excessive maintenance time due to condensation and clogging.
It is suitable for monitoring many common gases and vapors. The analyzer is unaffected by the temperature of the process and can sample streams up to 700°C.
The CalorVal employs customer-supplied nitrogen to drive its integrated air-aspirated sampling system. This method is simple, has no moving parts and requires very little maintenance. Auto-calibration solenoids which allow remote activation of calibration tests are standard.

The microprocessor-based control unit controls the sample flow and monitors many other functions of the analyzer such as operating temperature, calibration and the flame. Deviations or malfunctions are signaled as service-needed or fault events via LEDs and relays.

The system includes six relays: single-pole, double-throw relays for Low Limit Alarm, High Limit Alarm, Fault; and single-pole, single-throw relays for Horn, Calibration-in-Progress and Service Needed. Other standard outputs include a 4-20mA analog output and an RS-485 serial port with Modbus RTU protocol. Digital remote access and control is available.

Measurement Range 0-1300 BTU/ft3 (equivalent to 48 MJ/m3 oder 13,4 KWh/m3)
Optional: 0-2500 BTU/ft3
Repeatability ± 1% of full scale
Zero Stability ± 1% per month
Span Stability ± 5% per year
Response Time T90 ≤ 10 Sekunden (measured from sample inlet)
Operating Temperature 120°C
Power Requirements 120 VAC +10%-15% 50/60 Hertz or 230 VAC +10%-15% 50/60 Hertz
400 Watts maximum, 200 Watt typical
Sample Gas Pressure Nominal range: 0 to +70 mbarg
Maximum deviation to nominal: ± 35mbar
Sample Flow Rate Typical 1,3 l/min ± 0,5 l/min
Fuel Gas Hydrogen min. 99,99% purity, inlet pressure: 2,8-3,1 barg
Consumption: typical 25 ml/min,
Nitrogen Clean, dry Nitrogen at 1,4 barg inlet pressure
Consumption approx. 25 l/min
Combustion Air Innlet pressure 1 barg, consumption 700-800 ml/min
Ambient Temperature Range -20°C to +65°C
Relays Six relays for: Low Limit Alarm; High Limit Alarm; Fault; Horn; Calibration-in-progress and Service-needed
Rated 60 Watt maximum
Analog Output 4-20mA, non-isolated, 275 Ω max.
Serial Interface RS-485, half-duplex, Modbus RTU
Sample Train Material Hard-coat aluminium, stainless steel, Viton
Enclosure rating Standard: IP 54 (NEMA 12/13) for indoor use
Optional: IP 65 (NEMA 4X), corrosion resistant, for outdoor use
Dimensions 406mm H x 307mm B x 216mm T
Weight approx. 20 kg
Approval ATEX: Ex II 3(2) G Ex nA nC d IIB+H2 T4, Ta = – 20°C to + 65°C, IP 54