Cooper Instruments DFI-100 Installation Manual

DFI 100 HAND-HELD DIGITAL SIGNAL CONDITIONER USER’S GUIDE

1.0 INTRODUCTION

1.1 Overview

The Cooper Model DFI 100 is a complete hand-held portable signal- condition er/indicator for use with strain-gage
transducers. It provides an excitation supply for such transducers, amplifies the transducer’s output and indicates
this reading in engineering units. It can indicate this reading in a continuous fashion (tracking mode) or display only
the highest reading (peak mode) using a switch to make the selection.

Other features of the instrument include:

• 3 ½ digit liquid-crystal display

• use of a standard 9-volt battery

• low-battery warning indication

Though Model DFI 100 is small, it is a full signal conditioner, providing adjustment for zero, span, scaling and
switch-selected gain. It is useable with a wide variety of transducers types, and is the ideal instrument for the
technical person who must travel and take readings from a wide variety of transducers.

1.2 Specifications

Signal Conditioner

Excitation Voltage (To Transducer) 2.46 VDC
Minimum Transducer Impedance 120 ohms
Input Signal Sensitivity for Full-Scale
Indication
Peak Detector Bleed-Off Rate <0.01% Per second

Display

Type 3 ½ digits LCD, plus optional dummy zero
Low Battery Indicator Yes
Over-range Indicator Blinking digits
Digit Height 0.5”
Conversion Rate 3 readings/second

Physical Characteristics

Size 3.6” wide x 6.75” long x 1.75” high
Enclosure Material ABS impact-resistant plastic
Transducer Connector Four color-coded binding posts capable of spade lugs, banana plugs,

Power Supply 9-volt battery (NEDA 1604)
Battery Life 15 hours minimum with 350-ohm transducer impedance

0.5 to 8 mV/V

alligator clips, and stranded or solid wire

CF 02 1 Rev. A Jan 2002

1.3 Layout

1.3.1 Front Panel Controls/Indicators

ON/OFF Switch The ON/OFF switch controls power to the instrument from the battery.
[SHUNT CAL]
Switch
[PEAK/TRACK]
Switch

[ZERO]
POTENTIOMETER
[SPAN]
POTENTIOMETER

“LO BAT” Indicator This indication appears in the upper-left of the display and indicates when the battery

This switch connects the instrument’s shunt calibration resistor to the transducer and is
used during setup. See “SETUP” for more information.
The PEAK/TRACK switch selects the mode of operation of the instrument. In the TRACK
mode, the instrument’s display will continuously follow the transducer reading. In the PEAK
position, the instrument will retain and display the value of the most positive value detected
during operation. To reset the peak, switch the PEAK/TRACK switch to the TRACK
position. (A slight decay of peak value displayed over an extended period of time is
normal).
The ZERO potentiometer is used to obtain a zero indication, thus canceling drifts or offsets
that could exist in the instrument or transducer.
The SPAN potentiometer adjusts the fine gain or the amplifier. It is used to make certain
that the reading obtained from any transducer can be scaled to the proper level on the
display.

voltage is getting low.

-IN

ON

OFF

ZERO

+IN

SHUNT

CAL

+EX-EX

SPAN

PEAK

TRACK

+ Excitation

+ Signal

PIN OUT AS SEEN LOOKING INTO THE

CONNECTOR ON THE METER FROM

THE OUTSIDE REAR OF CASE

Wiring Fo r Mating Conn ec tor

4 Pin Mini

Din Connector

- Excitation

- Signal

LOOKING INTO THE MATING CONNECTOR

FROM THE F R ONT OF THE CASE W ITH

THE BOTTOM PLASTIC RECTANGLE TAB

Rectangle Tab

- Excitation

-Signal

+ Excitation

+Signal

Figure 1-Layout

1.3.2 Connection Terminals

On the top of the instrument are four binding-post connectors for the transducer connections. Labels descri be the
function of each of the terminals.

Instrument Transducer

+EX (+) Excitation

-EX (-) Excitation
+IN (+) Output

-IN (-) Output

Table 1: Transducer Hookup

CF 02 2 Rev. A Jan 2002