Building EcoPhys Equipment

EcoPhys EquipmentAs ecophysiologists we routinely need to develop unique equipment and equipment combinations. Our lab is dedicated to providing the community with the design details of the equipment we build so that you don’t have to reinvent the wheel. Here is a some of the equipment we have build or are building:

  • Scholander-type pressure chamber  (under construction)
  • Lab VPD measurement chamber (under construction)
  • Custom gas exchange/fluorescence chamber for LI6400
  • Constant flow porometer (it works!)
  • Gas mixer for gas exchange measurements capable of independent control of VPD, CO2 and O2.


PARdot – light (PAR or PPFD) sensors

We have funding from the International Wheat Yield Partnership to build PAR sensors for use in determining light penetration into wheat canopies. Our sensors calibrate well, but are really no competition to the industry standards…except in cheapness (<$10):



Octoflux gas exchange system

Tom Buckley and I have developed an Octoflux system of eight gas exchange chambers connected to one set of air supply and IRGA’s. I’ve milled and designed the chambers (see below). Tom has really done the difficult work of integrating these into the actual Octoflux system of his design. The chambers are aluminium, and need to be nickel plated.

Full gas exchange chamber parts (this is one of eight)
The assembled components


Most cheap, awesome datalogger box ever, in the whole world

(did I mention cheap?)

In searching for a waterproof, strong and cheap datalogger box (<<$10), we came up with the following:

A cheap, everything proof datalogger enclosure

The system is – from top to bottom – just a PVC pipe end cap, a PVC pipe, a PVC unthreaded to threaded converter, a PVC reducing brushing (that reduces to a small NPT thread), and a cable gland (almost all parts are available from McMaster-Carr, the cable gland can be found elsewhere).

The system is then assembled with PVC cement. The brushing can be removed to access the datalogger (Arduino etc), and the cable gland can be tightened around any cables to form a water tight seal.

The datalogger intended for this enclosure is a multiplexer built of IC’s:

multiplexer made from ICs

‘BeanOCart’ highish throughput phenotyping system

Viviana and I built the BeanOCart to measure her field experiment in 2015. The system wheels through the field, measuring two rows of beans. The sensors include a weather station and two sets of: canopy temperature, NDVI, PRI, and ultrasonic canopy height sensor, and canopy cover using the automated camera. All are integrated with a CR1000 datalogger, and plot number encoded via a plus or minus consecutive numbering switch. The system worked incredibly well, but does not have a steering capability, thus ideally it runs down long, long rows. Th system is modular and can be adjusted to any row width or crop height (<1.5m).

Vivi testing the’BeanOCart’ in a corn field

Leaf boundary layer conductance sensors

These devices use the heated plate principle of Grace et al.’s (1980) for measuring boundary layer conductance of leaf replicas. Here we constructed a round ‘leaf’ with grooves milled in it to hold thermistor temperature sensors and resistive heating wire. With two mirrored plates glued together, and two replicas, one can be heated for a few seconds and the other unheated. The relative dissipation of the heat indicates how boundary layer conductance responds to wind and canopy effects.

‘Leaf’ replica with heater and thermistors. This view is of the milled groove on the inside of the replica. It is circular so that boundary layer conductance doesn’t change with wind direction.
The two ‘leaf’ replicas in action in a lima bean field. They are alternately heated to measure boundary layer conductance.