Mecmesin Basic Force Gauge-HS Mk3 User manual

Contents
Powering the Gauge 2
Using the Gauge 3
Optional Settings 8
Dimensions 10
BFG-HS Specification Table 11
Introduction
Thank you for choosing the Mecmesin Basic Force Gauge-
High Specification (BFG-HS) instrument. With correct use and
regular re-calibration it will give many years of accurate and
reliable service.
The Mecmesin BFG-HS is a member of a series of highly
versatile display units. By using the latest integrated circuit
technology it has been possible to produce an
instrument which can be used to measure tensile and
compressive forces accurately, whilst being simple
to use by the operator.
Before Use
Upon receiving the unit please check
that no physical damage has occurred
to the packaging material, plastic
case or the instrument itself. If any
damage is evident please notify
Mecmesin immediately.
Operation
The most commonly used features
such as displaying force, peak hold, zero
and changing of displayed units can all be done by pressing
a single dedicated key on the front panel.
For less frequently used features a number of "hot keys" are
provided, whereby the operator simply presses and holds 2
keys to enable a gauge option.
Page 1

Powering the Gauge
Fitting and charging of
rechargeable batteries
Mains operation
Fitting of alkaline batteries
Low battery symbol
The BFG-HS is supplied with a set of 5 Nickel Metal Hydride
AAA rechargeable batteries. For safety reasons during
transportation the batteries are shipped discharged. To obtain
maximum battery life we recommend that you charge them
with the charger/adaptor supplied for at least 14 - 16 hours
when you first receive the BFG-HS.
To insert the batteries you must first remove the battery cover
on the rear of the gauge by undoing the 2 retaining screws.
Fit the 5 batteries in the battery holder ensuring that you
observe polarity and the batteries are placed on top of the
‘release tag’.
To remove the batteries simply pull the ‘release tag’ and they
will be freed from the spring-loaded contacts.
Refit the battery cover and tighten the 2 retaining screws.
Connect the mains adaptor/charger to the BFG-HS charger
socket and charge the batteries for 14 - 16 hours. Only use
the adaptor/charger supplied.
The BFG-HS can also be powered directly from the mains.
This can be achieved with or without the rechargeable
batteries being fitted. Connect the mains adaptor/charger to
your mains supply. Only use the adaptor/charger supplied.
If rechargeable batteries are fitted, a trickle charge will be
applied to the batteries.
The BFG-HS can also be powered by AAA 1.5V alkaline
batteries (not supplied). For the fitting of alkaline batteries,
follow fitting instructions as per rechargeable batteries above.
Warning: When alkaline batteries are fitted, the mains
adaptor/charger must NEVER be connected to the BFG-HS
due to risk of acid leakage which could damage the
instrument.
If the low battery symbol appears on the display the accuracy
of the loadcell reading may be compromised. The gauge
will power down after a short period of time.
Page 2

Using the Gauge
Fitting accessories
Mounting to a test stand
Powering up
Affix either the short extension rod (30mm long) or the long
extension rod (130mm long) to the loadcell probe in the hole
at the bottom of the gauge by tightening it gently with the
fingers.
Your chosen grip or accessory may now be connected to the
extension rod.
Note: When fitting a grip ensure that it is screwed finger-tight
only. Excessive torque can damage the loadcell.
On the rear of the gauge there are two M5 threaded holes,
which can be used for mounting the gauge to a Mecmesin
test stand.
Each Mecmesin test stand is supplied with a dedicated
‘dovetailed mounting bracket’ and screws for this purpose.
If you wish to mount the gauge to another type of stand,
ensure that the screws used are threaded into the gauge to a
maximum depth of 5.5mm. The final thread is peaned but if
screws are fitted beyond this depth, damage to the loadcell
will occur.
As shown in Figure 1 the control panel has 6 keys:-
To power up the gauge press
the red key. A short self
test runs during which the
display will show the model
and capacity in Newton’s.
MAX
UNITS
TXD
ZERO
RESET
BFG
200
N
fig.1
b
Page 3

After the self test, providing no load has been applied to the
instrument, the display will show all zeroes. This is because
the gauge re-zeroes itself during the self test routine.
If a force is applied perpendicularly via the sensor probe
(hole at bottom of BFG-HS), the reading on the display will
register the applied force.
* Do not overload the transducer, as this will cause
irreparable damage.
Forces greater than 120% of full-scale will produce an
audible beep until load is released and an OL symbol will
appear on the display
for 30 seconds .
Forces greater than 150% of full-scale will produce an
audible beep until load is released and an OL symbol will
appear
permanently on the display. Consult your supplier to
arrange repair.
To power down the gauge press the red key.
Tensile forces are displayed on the BFG-HS and recognised
by the symbol
Compressive forces are displayed on the BFG-HS and
recognised by the symbol
MAX
13.45
N
▲
▲
Fig. 2
Symbol for
tension
Unit of
measurement
Load indicator bar


Please note that a BFG-HS
measuring very low forces may
not show zero if it is moved
during the self test routine. Once
it is properly mounted and
zeroed the reading will be stable
Display of Tension/
Compression
If the BFG-HS has suffered a
serious overload condition, the
load indicator bar will be
partially displayed even when no
load is present. This is a warning
that the load cell is damaged
and you should immediately
contact your supplier to arrange
repair.
b
Page 4



Zeroing the Gauge
Changing the unit of
measurement
Max (Peak) Readings
"Max" mode
A load indicator bar alerts the operator to how much load
has been applied to the transducer. As the load approaches
the maximum rating of the transducer, the indicator bar
changes appearance when above approx. 80% of the rated
capacity. This warns the operator that steps should be taken
to prevent excessive load being applied.
For tensile forces the indicator bar is solid then dotted. For
compressive forces the indicator bar is dotted then solid – see
fig. 3b & 3c
During the operation of the gauge it is often necessary to
zero the display – e.g. when you wish to tare out the weight
of a grip, so it does not become part of the measured
reading. Press and release the ZERO key. The display will
blink momentarily as the zero operation is carried out.
You can choose from the following units of measurement
depending on the capacity of your gauge: millinewtons,
kilonewtons, newtons, gram-force, kilogram-force, ounce-force
or pound-force.
To change the display units press and release the UNITS key.
Each successive key press will select the next available units
until the gauge returns to its original setting. The BFG-HS
automatically converts readings as new units of measure are
selected.
The gauge detects and stores maximum (peak) force in both
compressive and tensile directions.
Press the MAX key. The display will show the word MAX
together with the highest tensile force and the highest
compressive force detected during the test. The current
load being applied to the transducer is also displayed.-
see fig 3a overleaf
Page 5

Press the MAX key again and the display will show the
maximum tensile force identified by the symbol.
Press the MAX key again and the display will show the
maximum compressive force identified by the symbol.
MAX
Fig. 3c
max compression
reading
MAX
42.95
N
MAX
▲
▲
Fig. 3b
max tension
reading
MAX
13.45
N
▲
▲
MAX
42.95
185.6
▲
▲
▲
▲
Fig. 3a
max tension
reading
max compression
reading
Load currently
applied to load
cell


Dual Max
Max Tension
Max Compression
Page 6

Press the MAX key again and the word MAX has now
disappeared from the display. The display will now indicate
forces applied in both directions as they are applied to the
transducer and maintain a "running" display.
Press the RESET key to clear both maximum registers and
prepare for detecting the next maximum readings.
The BFG-HS has RS232, Mitutoyo and analogue output
signals. It is possible to transmit the displayed reading to
peripheral devices (e.g. PC, printer) by pressing and
releasing the TXD key.
Displayed readings can also be requested individually from a
PC via the RS232 interface by sending a"?" (ascii D63 [3fh]
character.
For sending a continuous data stream to a PC, press and
hold the TXD key for 2 seconds then release. TX will now
appear in the display to indicate that data is being sent. To
stop sending data, simply press and release the TXD key, at
which point TX will disappear from the display.
Please note that the continuous data stream only starts when
approx. 2% of the rated capacity of the gauge is reached.
"Normal" mode
Data Output
BFG-HS uses 9600 Baud 8 data
bits, 1 start bit 1 stop bit and no
parity
A full range of data cables are
available to connect your gauge
to peripheral devices – contact
your supplier.
Page 7

It is possible to activate a backlight on the BFG-HS display.
Press and hold RESET whilst powering up the BFG-HS with
the key. The backlight is now operating.
Please note that battery consumption is doubled when using
the backlight.
To conserve battery power, it is possible to activate an Auto-
off function so that the gauge powers down after 2 minutes
since the last key press.
Press and hold ZERO whilst powering up the BFG-HS with the
key. The symbol Ao will appear in the display to indicate
Auto-off is active.
For tension applications it is often desirable to reverse the
display, so that the operator can read it more comfortably.
By pressing and holding MAX whilst powering up the BFG-
HS with the key, the display is inverted.
If you suspect that your loadcell transducer has sustained an
overload it is possible to check the status of the loadcell
immediately.
Symptoms of overload may be (a) OL in display (b) buzzer
sound (c) probe not aligned perpendicularly to gauge (d)
load indicator bar present even under zero load.
Place the gauge horizontally on a flat level surface. Press and
hold UNITS until the password menu appears with 0000 in
the display. Press ZERO four times and you will now see 2
values shown as %.
The upper value shows the % offset when the gauge was last
successfully calibrated. The lower value shows the % offset
currently present on the gauge.
Optional Settings
Backlit
Display
Auto-off
Invert Display
Loadcell
Diagnostic test
An instrument showing an
overload condition cannot be
relied upon to provide accurate,
repeatable measurement –consult
your supplier.
b
b
b
Page 8

If the % offset is between 5% - 10% please contact your
supplier to arrange a recalibration of your BFG-HS.
If the % offset is greater than 10% please contact your
supplier to arrange for a loadcell replacement. These values
are given as an indicator only – the need for
calibration/repair may vary according to the individual
characteristics of the load cell.
MAX
-2.7:%
0.5:%
Fig. 4 upper value = offset
when last calibrated
lower value = offset
currently present on
gauge
Page 9

Dimensions
Allocation for the pins on the
female 15 way ‘D Type’
Communication Connector
Pin Out:
1 Analogue Output
2 RS232 Transmit
3 RS232 Receive
4 Mitutoyo Clock Output
5 Mitutoyo Ready Output
6 not used
7 not used
8 not used
9 not available
10 Ground
11 Mitutoyo Request Input
12 Mitutoyo Data Output
13 not used
14 not used
15 not used
Front View
202mm
Side View
30.9mm
16
20
Rear View
77mm
LOADCELL STUD:
THREAD = M6 x 1.0p
OPTIONAL DOVETAIL BRACKET
FOR MOUNTING ON TEST STANDS
MAXIMUM SIZE SCREWS = M5x10 SOCKET CAP HEAD SCREW
57mm
75mm
TAPPED HOLE:
THREAD M5 x 0.8p x 5.5mm DEEP
Page 10

BFG-HS Specification Table
Range & Resolution
Model no: mN N kN g-f kg-f oz-f lb-f
BFG-HS 10 10,000 x 2 10 x 0.002 - 1,000 x 0.2 1 x 0.0002 35 x 0.01 2.2 x 0.0005
BFG-HS 50 50,000 x 10 50 x 0.01 - 5,000 x 1 5 x 0.001 180 x 0.05 11 x 0.002
BFG-HS 200 - 200 x 0.05 - 20,000 x 5 20 x 0.005 720 x 0.2 44 x 0.01
BFG-HS 500 - 500 x 0.1 - 50,000 x 10 50 x 0.01 1,800 x 0.5 110 x 0.02
BFG-HS 1000 - 1,000 x 0.2 1 x 0.0002 - 100 x 0.02 3,500 x 1 220 x 0.05
BFG-HS 2500 - 2,500 x 0.5 2.5 x 0.0005 - 250 x 0.05 9,000 x 2 550 x 0.1
Accuracy:
±0.25% of full-scale, ± least significant digit
Calibration temperature: 20°C ±2°C
Operating temperature: 10°C - 35°C
Temperature shift at zero load: ±0.09% of full-scale/°C
Output:
RS232-C ….. 8 data bits, 1 Start bit, 1 Stop bit, no parity
Digimatic (Mitutoyo) format
Analogue … 2.5V at zero load, ±1.5V approx. for full-scale tension/compression
Page 11

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S.I. Instruments
256 South Rd. Hilton
South Australia 5033
Ph [phone]
[email protected]
www.si-instruments.com.au