Delta-T Devices AP4, User Manual

Page: 25 / 64

HOW TO READ
Page 25
HOW TO READ
This section describes how to take readings by driving the porometer around the READ
loop, and what settings can be changed.
WARNINGS
•
Keep cup relative humidity (RH) below 80% if possible.
•
Avoid exposing the cup to organic solvents and smoke.
•
Keep calibration plate clean, avoid finger grease.
•
Remove excess water from paper pad before taping it to the calibration plate.
•
Recalibrate whenever the temperature changes by more than 5°C.
•
Recalibrate when changing RH set point.
•
Do not allow battery to remain discharged.
•
Prepare and plan your experiments: see Planning Your Experiment on page 39 and
Hints and Tips on page 42.
THE READING LOOP
Readings can be taken one handed. Just press the GO button on the head.
YOUR
ACTION
POROMETER
ACTION
DISPLAY
TITLE
Press ON Porometer wakes up MAIN MENU
Press GO Selects READ loop INSERT LEAF
Insert leaf Waits …
Press GO wait
Selects START option
Starts cycling READING CYCLE
updated with every reading
Wait 4 or 5 cycles until readings are stable or until double beep sounds
Press GO
Stops cycling and
ACCEPTS last reading
STORE READING
Press GO
STORES last reading
and PAR* reading. Loops
back to beginning of READ
cycle
returns to
INSERT LEAF display
*Notice that the PAR light sensor reading changes if you change the lighting. The only value which
will be saved is the one existing at the instant when you press GO to select STORE. So position the
head thoughtfully when you do this, level with the leaf if possible.