12
Taking Readings
When in standard reading mode, the LCD of the TCM500
will display the turf color data and a running average.
This value remains in the meter’s short-term memory until
it is deleted or the meter is shut off (see Keypad
Operation, p. 10). If the data logger is enabled, the data is
also recorded in the logger’s memory.
Do not take measurements when dew is present or when
turf is wet following irrigation. Since moisture on turf
affects the amount of reflected light from the samples,
meter readings will not be accurate.
Readings will
NOT
be affected by ambient light (sun
versus clouds) conditions. The TCM 500 has its own
internal light source, allowing measurements to be made
any time.
When measuring “taller” grass, it may be necessary to
press down on the meter/sample such that ambient light is
blocked out. Excessively bright ambient or reflected light
will saturate the light sensors and thereby cause invalid
readings. When the light sensors near the saturation point,
an LCD message of
!!ERROR!!
,
EXCESSIVE LIGHT
will appear.
Meter Display
The first line of the LCD will be the index reading in the
currently selected mode (RED/NIR, NDVI, Grass) (see
MODE
key, p. 11). The second line gives information
about the running average (
AVG
) and current sample
number (
N
).
As each reading is taken, i.e. each time the trigger is
released, the
INDEX
reading is incorporated into the
Standard Reading Mode
