Spectrum Technologies Field Scout TCM 500 User Manual

Catalog #2975NDVI

Spectrum

Technologie s, I nc.

2

Contents

General Overview 3
Computer Interface/Changing the Battery 5
Identifying the Correct Com Port 6
Initial Startup 7
Connecting to a GPS Unit 8
Keypad Operation 10
Standard Reading Mode 12
Field Scout Software Toolbar 14
Meter Settings 16
Data Files 17
Meter Indexes 18

Specifications 19
ERROR messages 20
Appendix 1: Time Zone Corrections 21

Frequently Asked Questions 22
Service and Support 23

3

General Overview

Turfgrass quality is visually evaluated by human assessors
based on a scale of 1 (poorest, the grass is dead) to 9
(ideal, the grass if of outstanding quality) using a common
assessment method. A rating of 6 or greater indicates
adequate turf quality. Because this evaluation practice is
subjective, individual biases are inevitable and lead to
some level of inconsistency, even among the most highly
trained observers. This variability led to the need for a
more objective evaluation technique.

To answer this need, researchers have developed the
Normalized Difference Vegetative Index (NDVI). The
Field Scout TCM 500 “NDVI” Turf Color Meter
measures reflected light from turf grass in the red (660
nm) and near infrared (850 nm -NIR) spectral bands.

Because chlorophyll absorbs the red band (660 nm) of
incoming radiation, the reflectance at that wavelength is
relatively low due to the strong absorption of the light by
the plant pigments. The high reflectance in the NIR (850
nm) band is caused by the cellular structure of the plant
leaves, particularly the spongy mesophyll leaf structure.

4

Features

• A measuring target approximately 3 inches (7.6 cm) in
diameter.

• Consistent internal light source that negates the effects
of sunny versus cloudy conditions.

• Red & NIR data is presented in three forms: Percent
reflectance (0.0 to 99.9) of Red and NIR, NDVI (0.000
to 1.000), and Grass Index (ie. 1.00 to 9.00).

• GPS/DGPS can be used - requires GPS/DGPS cable
(item 2950CV5).

• A running average is calculated and displayed as
multiple readings are taken.

• Data is stored in comma-delimited text files. They can
be opened and processed with any spreadsheet,
graphing, statistical, or word processing program.

5

Computer Interface/

Changing the Battery

Software Installation

Insert the CD for Field Scout software into your PC’s disk
drive. If auto-start is not enabled on your computer, select
Run from the Start menu and type D:\Setup.exe
(Substitute the appropriate drive letter for your CD drive).
Click OK and follow the instructions on the screen.

The meter’s data port can be accessed by removing the
plastic screw to the left of the handle. It is through this
port that the meter is connected to either a PC or to a GPS
unit. The meter must be turned off before attempting
communication with the software.

Connecting to a PC

The Field Scout software comes with a gray PC interface
cable. This cable connects to the 9-pin serial port of your
computer and to the meter’s computer port. The meter’s
configuration can be modified by clicking on the Meter

Settings button (see Meter Settings, p. 16). The Com
Port, Meter Type, Download, Clear Memory and Me-
ter Settings buttons are explained in the Field Scout Soft-

ware Toolbar section (p. 14).

Changing the battery

The battery compartment is accessed by removing the 4
philips-head screws on the underside of the meter and re­moving the bottom plate. The TCM 500 meter is powered
by a 9-V battery.

6

Initial Startup

Allow the temperature of the TCM 500 meter to
equilibrate with the turf environment prior to sampling.

When the TCM 500 meter is first turned on, the battery
strength (Battery at __ %) will appear on the LCD. The
available battery power percentage assumes alkaline
batteries are being used. If rechargeable NiCd batteries
are installed, the available battery power will be more than
displayed. If the data logging option has not been
enabled, the unit will then proceed to the standard reading
mode.

In order to record data and global positioning system
(GPS) coordinates, the data logger must first be enabled
through the software (See p. 16). If the data logger has
been enabled, battery strength and the amount of
remaining memory (Memory __ % FULL) will be
displayed. If GPS data is being recorded as well, the
meter will display the status of the GPS signal. The meter
will then proceed to the standard reading mode.

IMPORTANT: The GPS unit must be powered up,
have located the satellites and been connected to the meter
before turning the meter on (see Connecting to GPS Unit
p. 8).

7

Identifying the

Correct Com Port

The computer
Communications Port to
which the PC-3.5 serial
cable is connected can be
identified by using a paper
clip.

1. Disconnect the serial
cable from the meter.

2. To bring up the Port Selection screen, click on the
Com Port Button, select the com port to be tested and
click the Port Test button. Click the Test Port Now
button. If the message “Connection OK” is displayed,
another device (such as a modem) is probably connected
to that port. If the message “No Connection” is displayed,
this port may be the one connected to your serial cable and
you can proceed to the next step.

3. Place a paperclip on the end of the serial pin so that it
touches both the tip of the pin and the metal area between
the two black rings. Again click on the Test Port Now
button. If the message “Connection OK” now appears,
this is the com port connected to your serial cable.

paper clip
or wire

NOTE: The meter does not short-circuit the serial pin.
Therefore, when the Test Port Now button is clicked
while the meter is connected, the “No Connection”
message will be displayed.

8

Connecting to a

GPS Unit

The data logger function must be enabled using the Field
Scout software in order to record a GPS signal (see Meter
Settings p. 16).

The GPS unit must be plugged into the TCM500 meter
and working when the meter is first turned on. If a GPS
signal is found at startup, the logger will search for a GPS
signal for every reading. If no GPS signal is found when
the meter is first turned on, the meter will not search for
one when taking readings, thereby saving time when
taking readings. In this case the LCD will display the No
GPS Found message.

If the GPS signal is found while taking geo-referenced
readings, the LCD will briefly display the message,
“Reading GPS ..” before displaying the measurement. If
the GPS signal is lost during a series of readings, or if the
specified differential correction is not found, the LCD will
read “Reading GPS .. ERR” before returning to
measurement mode. In this case, the data will be recorded
without latitude and longitude. During subsequent
readings, the meter will again search for a GPS.

GPS Setting

Your GPS unit must be set for NMEA 0183 input/output
messages. If the meter has trouble receiving the GPS
signal, check that the GPS unit has the following settings:

Data bits: 8 Stop bits: 1
Baud rate: 4800 bps Parity: None
Timing: 1 second GGA data string