Select Page

ProCO2 120ppm

Animal Chamber Off-Gas Limit Controller

  • Animal off-gas maintenance
  • Fits/controls CO2 in most semi-sealable chambers
  • Assures environmental quality
  • In vivo applications
  • Reduced stress on animals for definitive results
  • Prevent artifactual hypercapnia in vivo
When you publish your data generated with this equipment, please copy and paste as follows for proper citation in your manuscript.

ProCO2 120ppm Overview


The ProCO2 120ppm is a parts-per-million limit controller primarily used for assuring consistent and acceptable off-gas levels in a variety of animal enclosures.


The ProCO2 120ppm gas controller fits and controls CO2 inside any semi-sealable enclosure. Whatever size, shape, rigidity, or isolation level, most chambers can be fitted in minutes. The ProCO2 120ppm works from outside the host chamber by remotely sensing the CO2 inside the chamber. The gas controller for animal lab chambers infuses compressed dry air to lower CO2 levels.


The ProCO2 120ppm can monitor and control off-gas alongside any BioSpherix oxygen or OxyCycler AT Series controllers. Maintain air quality while running O2, NO, or CO sensitive experiments without disturbing their levels.


The ProCO2 120ppm gas controller gains feedback from the CO2 sensor in order to precisely regulate gas infusion according to the set point. No gas is ever wasted.


CO2 is quickly pushed to set point and held beneath the limit indefinitely. Any disturbances are instantly detected and corrected immediately. Calibration and gas supply must be checked occasionally. Everything else is automatic with the gas controller for animal lab chambers.


• When ambient CO2 is raised.

• In a closed chamber, it can restore and maintain air at OSHA human limit equivalent CO2.

• Where CO2 generative processes need to be countered, the ProCO2 120ppm can hold CO2 stable.

• Run it continuously year-round, or on occasion as needed. No other CO2 controller offers so much value.




CONTROL RANGE: 10 to 10,000ppm (depending on the power/ load balance)

ACCURACY: ±150ppm (@0ppm) to ±350ppm (@1000ppm) @25C and 1013hPa


CARBON DIOXIDE SENSOR: various application specific sensors are available.

GAS SOURCE: compressed gas tanks, liquid carboys (from headspace), or generators.

GAS SUPPLY: compressed dry air (CDA).

GAS SUPPLY LINE: 1/8” I.D. hose pressure rated to 25 PSIG.



GAS CONSUMPTION: depends on (1) size and leakiness of host chamber, (2) frequency and duration of opening chamber doors, and (3) carbon dioxide level controlled.

GAS SUPPLY HOSE FITTING: 1/8” hose barb.


INFUSION TUBING DIAMETER: 1/4” O.D. x 1/8” I.D. (special tubing sizes available).

INFUSION TUBING LENGTH: 10 ft. (custom lengths available).



ALARM OUTPUT: audible 40dB alarm and visible flashing indicator.

ALARM MODES: process high, process low, deviation high, deviation low, deviation band.

WEIGHT: .7 lbs (Controller Only)

DIMENSIONS: 1.5”H x 3.5”W x 7”D

Sensor Operational Parameters

HOST CHAMBER SIZE: depends on the chamber gas dynamics and carbon dioxide level controlled.

HOST CHAMBER TEMPERATURE: -20-50°C (depending on sensor).

HOST CHAMBER CO2: 0-99% (depending on sensor)

Optional: Windows® based software package that provides trend plotting, data logging, and remote operation via RS connection to your PC. Multiple ProCO2 120ppms can be daisy-chained via optional RS-485 interface.

Front Panel


1. Bleed Valve: Bleeds gas (nitrogen or oxygen) out of gas supply line. Used for calibrating sensor and depressurizing gas supply.

2. Control Indicator Light: Flashes when gas is infused.

3. Digital Display: Bright green 0.4 inch digits. Continuously displays CO2 concentration at sensor, unless pre-empted by other operations. Displays menu items and settings during programming.

4. Alarm Indicator Light: Flashes when alarm output is actuated.

5. Gas Switch: Manually overrides controller to shut off gas.

6. Alarm Switch: Manually overrides controller to shut off alarm.

7. Touch Keys: 3 amply spaced tactile keys for setting configuration and control parameters.

8. Bleed Outlet: 1/8” hose barb where gas bleeds out from bleed valve. Calibration tubing for sensor attaches here.


Back Panel


9. Sensor Input Jack: Sensor cable connects here by twisting the sensor cable into the port until it pushes in and a “click” is heard.

10. Electrical Power Inlet Jack: Plug from 12VDC wall mount power supply connects here.

11. Gas Supply Inlet: Brass 1/8” hose barb where in-coming control gas supply line connects. Can handle up to 25 PSIG pressure.

12. Control Gas Outlet: Brass 1/8” hose barb where infusion tubing into host chamber connects.



proco2120ppm031. Set ProCO2 120ppm on or near host chambers and plug it in. 2. Mount the adapter plate to its host chamber. 3. Hook up gas supply.


proco2120ppm05Front Panel Interface All operators are conveniently located on the front panel. All connections are on the back panel, out of the way. Carbon Dioxide concentration at sensor continuously displays in bright green digits that can easily be read from across the room. Manual switch for gas provides convenient shut off. It saves gas when the chamber door is open. Just don’t forget to turn it back on! The alarm buzzer also has a manual switch. Calibration proco2120ppm06Use the calibration cup to expose the sensor to a calibration gas with a known CO2 level. There are no third party carbon dioxide analyzers needed.

How It Works

proco2120ppm04The ProCO2 120ppm attaches to animal chambers via an adapter plate. BioSpherix A-Chambers have a standard sized cut-out that accommodates all of our controllers. The ProCO2 120ppm works in semi-sealable chambers by forced displacement of gas via dilution with control gas. Pressure inside the chamber stays the same as pressure outside (normobaric). Dilution is a logarithmic process. The further the setpoint is from ambient levels, the slower it is reached, but closed-loop control is efficient. By constantly monitoring chamber CO2, it responds immediately to correct any disturbance from the set point. It automatically adjusts to different loads. In the process, it uses the least amount of gas possible. The ProCO2 P120ppm works day in and day out, year after year.


USE ANY GAS SUPPLY Conveniently utilizes gas from any source. Compressed gas is best in low consumption applications. Generator is best in high consumption applications. Liquid is best in between. SAVES ON GAS AND MONEY Chamber gas consumption varies widely, but in every case the ProCO2 P120ppm always and absolutely minimizes gas consumption. It’s maximally efficient! Gas costs are reduced to absolute minimum. SAVES MONEY Gas costs are reduced to absolute minimum.

proco2120ppm07The ProCO2 P120ppm is versatile; it works in any semi-sealable chamber. It works exceptionally well with BioSpherix A-Chambers (pictured above) that were designed specifically for animal experiments.


Power is a function of infusion rate of control gas. The higher the infusion rate, the faster to setpoint. Above: infusion rate #4>#3>#2>#1. Infusion rate is a function of control gas supply pressure. The higher the pressure, the higher the infusion rate. Maximum 25 PSIG provides 35 SCFH.


ProCO2 120ppm controls chamber carbon dioxide by infusing compressed dry air, displacing some of the current gaseous contents. Pressure inside the chamber stays the same as pressure outside. Dilution is a logarithmic process. The further away from ambient the setpoint is, the slower it goes. But closed-loop control is efficient. By constantly monitoring chamber carbon dioxide, it reacts promptly to hold CO2 beneath the set limit. It responds immediately to correct any increase. It automatically adjusts to different loads. And in the process, it uses the least amount of gas possible!

proco2120ppm08The setpoint of 1200ppm is automatically limited by the controller as soon as off-gases accumulate to that level. The variations caused by different animals and different activity levels are all eliminated and made constant at a 1200ppm limit by the controller, and it is done in the most efficient way possible. Able to work with any or all other controllers simultaneously controlling other gases at the same time.

Animal Off-Gas maintenance

CO2 is used because it is the best surrogate for all the other off-gases. CO2 is constantly exhaled in relatively high quantities, so by limiting CO2 within the chamber you can assume that all other off-gases will be fine. One exception may be relative humidity. When an excessive source of humidity such as overly moist litter (animal urination, water bottles dripping) or animal exposures that require activity (amount of moist air exhaled is increased), relative humidity may raise faster than ambient CO2. OSHA limits the indoor air quality for people to be no more than 1200ppm. The ProCO2 120ppm can easily maintain this setpoint (as well as higher/lower) for your valuable animal models.