Multichannel / Gas Switching Systems, Flux Monitoring & gas Pumps

Multichannel Gas Monitoring / Gas Switching Systems (Q-GSS), allowing to measure gas exchange across multiple samples using a single set of gas analysers. The Gas Switching Systems allow monitoring up to 8 different channels when e.g. used with a single Q-Box system, such as the Low Range RP1LP Insect Respirometry Package and the Animal Q-RP2LP High Range Respirometry Package. For packages such as the Q-NF1LP Nitrogen Fixation Package and the Q-Box CO650 Plant CO2 Analysis Package, the GSS allows up to 4 different samples to be tracked. The multiple channel systems allow simultaneous measurement of respiration (O2 and VCO2), nitrogen fixation, photosynthesis and transpiration on multiple channels. Two versions of the GSS are available:

• standard version designed for open flow measurements (Q-GSS), and a
• extended version that supports both open flow and stop flow (Q-GSS-SF) measurements.

A 3/4 L min-1 flow gas pump (Q-P651, see below), is utilized. The reference gas is transported through the Q-G261 low-pressure regulator to the flow meters. Each flow meter provides and controls the gas flow manually to its corresponding chamber. The output gas from all chambers is routed to the gas inlets on the gas switcher (two models: Q-G244 - 8 channels / Q-G243 - 4 channels). The software chooses the corresponding chamber, and its gas is sent through a solenoid valve linked to that channel to the analysers and flow monitor. The multiplexing between chambers is managed by the digital control unit (Q-C200) and the software. The other chambers are meanwhile vented to the atmosphere, guaranteeing continuous gas flow throughout all chambers and preventing the build up of high gas concentrations within chambers. Channel 1 serves as a reference channel as part of an Open Flow setup.

The Gas Switching System has an enhanced version (Q-GSS-SF) that caters to both Open-Flow and Stop-Flow (SF) measurements. The Stop-Flow setup is a more sensitive configuration, e.g. used to measure small, inactive samples in a closed chamber approach. Each chamber comes equipped with a solenoid assembly (Q-A380) that features two 3-way valves. The valves are used to stop the flow through the chamber, allowing e.g. CO2 to accumulate and O2 to be depleted. When deactivated, the gas is subsequently sent through the attached CO2 IRGA or O2 gas analysers etc. for measurement. The gas switching systems have three operational modes,

Q-P103 Gas Pump (0-1 L min-1), which utilizes a diaphragm-style design, can produce gas flows of up to 1 litre per minute. Its tranquil operation is ensured by rubber feet and an internal rubber pump mount. Luer-type gas inlet and outlet openings permit easy hooks up to any gas exchange system. A potentiometer allows precise regulation of pump speed, varying from 50 to 100%, to reduce the chances of unintended adjustments. Additionally, two needle valves located at the rear plate of the unit enable the precise adjustment of the gas flow rate. The internal outlet laminar dampening volume ensures the reduction of pressure pulses, rendering the device suitable for usage with laminar mass flow sensors. Possible applications of this gas pump include supplying gas to gas analysers, delivering gas to algal cultures or aquaculture, .... and serving as an essential component of Q-Box Research Packages.

Q-P651 Gas Pump (0-3/4 L min-1), as a diaphragm, oil-less pump, is used to supply gas to gas exchange systems etc. The maximum unrestricted gas flow generated by the Q-P651 pump model is ~3-4 Litres per minute (at ~330 mA).

• Maximum flow of 1 or 3-4 L min-1 under no load, depending on model
• Simple operation
• Quiet, diaphragm pump
• Two valves to adjust the inflow and outflow of gas
• Potentiometer allows accurate control of pump speed
• Internal outlet laminar dampening volume leads to reduced pressure pulses

Q-G268 Flow Monitor and Pump (2 LPM), seamlessly combining a digital mass flow meter and gas pump in a single instrument. The gas pump supplies gas to the flow monitor, allowing measurement and continuous tracking of flow rates in the range of 0 to 2 L min-1. Gas flow can be manually adjusted using the two needle valves on the rear of the instrument (see image of rear connector panel below). The analogue signal from the flow monitor is transmitted to a data interface, and displayed in the software. The flow monitors are factory calibrated. The software provides a specific calibration to convert voltage readings into flow rates measured in millilitres of gas per minute. Gas flow can be further controlled by manually adjusting the two needle valves on the rear of the instrument (see image below). To effectively monitor gas flow, the Q-G268 must be connected to a data acquisition interface (such as the Q-C610 LabQuest Mini) and compatible software, such as the C901 Logger Pro software or any other data acquisition software that accepts a 0-5 V analogue signal.

Q-G267 Flow Monitor and Pump (1 LPM), supplying gas to the flow monitor for measuring and tracking continuous flow rates within the range of 0 to 1 L per minute.

• Simple operation
• Two valve adjustment of gas flow in and out
• 1 or 2 L per minute max. flow (no load), depending on model
• Universal Luer Lock gas connectors
• Analogue output 0-5 V for flow measurement
• Flow rate calibrated in software
• Optional battery package for enhanced mobility 

Q-G266 Flow Monitor (1 L min-1) or Q-G265 Flow Monitor (2 L min-1), two gas flow monitor models ideal for measuring and tracking continuous flow rates in the range of 0 to 1 L/min or 0 to 2 L/min. Gas can be supplied to the unit's stainless steel Luer inlet port from either a pump or pressurised source. Each unit is factory calibrated; specific calibration values are supplied with each unit. Gas flow can be controlled by manual adjustment using a stainless steel needle valve on the rear of the instrument. To monitor gas flow, both models must be used with a data acquisition interface (e.g. Q-C610 LabQuest Mini) and software such as Q-C901 LoggerPro Software or any other data acquisition software that accepts a 0-5 V analogue signal.

• Easy to use 0-1 LPM or 0-2 LPM gas mass flow monitors, max. flow rate depending on model
• Factory calibrated
• Secure Luer gas connectors
• Manual adjustment of flow using a needle valve 
• Gas flow recording in software

Manual Flow Meter / Rotameter, for monitoring gas flow rates in various ranges at a maximum pressure of 101 kPa (14.7 PSI). These flow meters are precision instruments particularly suitable for metering carrier gases in chromatography, for indicating and controlling gases in manufacturing processes, and for measuring gas flow in systems for respiration and photosynthesis measurements. Flow meters are available in a variety of ranges for flow rates from 2 ml/min up to 10 L/min. Use Q-G262 Blow Off Valves to ensure that changes in the flow rate at one rotameter will not affect the flow rates of others, providing a reliable and independent control mechanism. For precise control and digital recording of gas flow rates, please see Digital Mass Flow Monitors.