LW Measurements PRW User Manual

PRW series

Bench Scale

User’s guide

UGPRW-E1.01

PRW serial bench scale user’s manual

Table of Contents

SECTION 1 INTRODUCTION……………………………………………………………1
SECTION 2 SPECIFICATIONS……………………………………………………..……2
SECTION 3 INSTALLATION……………………………………………………………….3
SECTION 4 KEY DESCRIPTIONS………………………………………………………5
SECTION 5 DISPLAYS…………………………………………………………………….6
SECTION 6 OPERATION…………………….……………………………………….…..7

6.1 Zeroing the display………………………………………………………………….7

6.2 Taring……………………………………………………………………………..…….7

6.3 Weighing a sample…….………………………………………………….………….7

6.4 Check-weighing…………………………………………………………………….8

6.5 Accumulated total……………………………………………………………………….9

SECTION 7 PARAMETERS………………………………………………………………10
SECTION 8 BATTERY OPERATION………………………………………………..…13
SECTION 9 RS-232 OUTPUT…………………………………………………………..14
SECTION 10 CALIBRATION……………………………………………………..……..16
SECTION 11 ERROR CODE…………………………………………………………17
SECTION 12 TECHNICAL PARAMETES…………………………………………….18

- I -

PRW serial bench scale user’s manual

SECTION 1 INTRODUCTION

The PRW series of bench scale provides an accurate, fast and versatile series of
general purpose weighing scale with units conversion and check-weighing functions.

All the keypads are sealed, color coded membrane switches and the displays are
large easy to read liquid crystal type displays (LCD). The LCD’s are supplied with a
backlight.

All units include automatic zero tracking, units conversion ,audible alarm for pre-set
weights, and an accumulation facility that allows the individual weights to be stored
and recalled as an accumulated total.

-1-

PRW serial bench scale user’s manual

Model

PRW-I

PRW-II

Resolution

1/3,000

1/6,000

Interface

RS-232 Output Optional

Stabilisation Time

1 Seconds typical

Operating Temperature

0°C - 40°C / 32°F - 104°F

Power supply (external)

115 / 230 Vac, 120 / 240 Vac, 50/60Hz, 10 watts

Calibration

Automatic External

Display

6 digits 22mm LCD display, attached backlight

indicator Housing

ABS Plastic,

Zero range

0mV~5mV

Signal input range

0~15mV

ADC

Sigma delta

Internal counts

600,000

ADC update

Max 60 times /second

Load cell drive voltage

Max 5V/150mA

Load cells

Up to four 350 ohms cells

SECTION 2 SPECIFICATIONS

-2-

EXC+

SEN+

SEN-

EXC-

SIG+

SIG-

SHIELD

5
5
3
2
4
4
1

LOAD CELL

PRW serial bench scale user’s manual

SECTION 3 INSTALLATION

GENERAL INSTALLATION

The scales should be sited in a location that will not degrade the accuracy.

Avoid extremes of temperature. Do not place in direct sunlight or near air conditioning
vents.

Avoid unsuitable tables. The tables or floor must be rigid and not vibrate. Do not
place near vibrating machinery.

Avoid unstable power sources. Do not use near large users of electricity such as
welding equipment or large motors.

Avoid high humidity that might cause condensation. Avoid direct contact with water.
Do not spray or immerse the scales in water.

Avoid air movement such as from fans or opening doors. Do not place near open
windows.

Keep the indicator clean.

Do not stack material on the scales when they are not in use.

INSTALLATION OF PRW SERIES

Please make the load cell connector from the load cell follow the drawing below
Attach the AC power adapter to the connector on the back of the indicator.
If you use PRW for a platform scale, you can use attached indicator bracket, this
indicator bracket is design for 38mm pole.

Load cell connect as below( 5pin air connecter)

-3-

PRW serial bench scale user’s manual

SECTION 4 KEY DESCRIPTIONS

Zero

Set the zero point for all subsequent weighing. The display shows zero.
A secondary function , of "Enter" key when setting parameters or other functions.

Tare

Tares the scale. Stores the current weight in memory as a tare value, subtracts the
tare value from the weight and shows the results. This is the net weight. Entering a
value using the keypad will store that value as the tare value.
A secondary function , of incrementing the active digit when setting a value for
parameters or other functions.

G/N

Press the key , the scale can to select gross weight or net weight after you tare a
weight.
Secondary function , In the setting mode, this key used to move active digits
right.

M+

To print the results to a PC or printer using the optional RS-232 interface. It also
adds the value to the accumulation memory if the accumulation function is not
automatic.

Secondary function ( C or ) , is to act as a clear key or to move active digits
left when setting values for parameters or other functions.

UNIT or U

Press this key to select the weight unit. Move the active digit left when setting values
for other functions.
Secondary function (ESC) , is to return to normal operation when the scale is in a
parameter setting mode.

ON/ OFF

Turn on or off the power.

-4-

PRW serial bench scale user’s manual

Battery low

stable

Check weighing

Weighing unit

BACK

SECTION 5 DISPLAYS

The LCD display will show a value and a unit to the right of the digits.
In addition there are labels for TARE, GROSS weight, Zero and for Low battery

-5-