Flintec LDU 68.2 - Manual (Page 6)

LDU 68.1 & 68.2 Technical Manual, Rev. 12 January 2010 Page 6 of 28
3. Introduction and Specifications
The model LDU 68.x is a precise digital amplifier for weighing and force measurements with strain gauge (SG)
sensors. The LDU 68.2 can be used for industrial applications,the LDU 68.1 can be used in legal for trade as
well as for industrial applications. The device features full multi-drop communications capability and can be
programmed via a straightforward ASCII command set.
The LDU XX.X series and the amplifier DAS 72.1 with on-board digital display, use the same command set.
You can connect up to 32 SG amplifiers of either the LDU XX.X series or DAS 72.1 type onto a single RS 485
bus. The LDU 68.x with its accurate A to D converter and an internal sample rate of up to 90 measurement
values per second, is particularly suitable for static or dynamic measurements and control purposes.
Specifications LDU 68.1 LDU 68.2
Accuracy class III -
Test certificate according OIML R76 10 000 Teile -
Linearity < 0.002 % FS
Excitation
5 V DC, load cells 350 – 1 150 Ohm (87,5 – 1 150 Ohm at supply
voltage up to max. 12 V DC); 6 wire technique
Analogue input range
±11 mV (bipolar; for weighing applications, force and torque
measurements)
Minimum input sensitivity 0.1 μV / d
Certified accuracy according OIML R76 1.0 μV / e -
Resolution > ± 130 000 counts (input); ± 100 000 counts (output)
Conversion rate 90 values/second internal, up to 90 values/second external
Digital filter IIR filter 0.2 to 5 Hz; Bessel; in 8 steps adjustable
Calibration By software via ASCII commands, sehr einfach durchführbar
Communication interface
RS485 oder RS422; Voll-Duplex oder Halb-Duplex;
9600 ... 115200 Baud; busfähig bis zu 32 Einheiten
Standard weighing functions Gross, tare, net, zero, etc.
Digital inputs
2x opto-isolated inputs, 10 ... 30 V DC max. 3 mA,
Status via software
Digital outputs 2x open collector outputs, < 30 V DC, max. 200 mA
Temperature effect on zero
Typical 7 ppm/°K;
max. < 10 ppm/°K Typical 25 ppm/°K;
max. < 50 ppm/°K
Temperature effect on span
Typical 2 ppm/°K;
max. < 5 ppm/°K Typical 15 ppm/°K;
max. < 30 ppm/°K
Operation temperature range –15 °C to +55 °C –15 °C to +50 °C
Storage temperature range –30 °C to +70 °C
Enclosure
Tinned steel enclosure, IP40 protection,
special IP65 housing on request
Dimensions and weight
82 x 31 x 6 mm, weighs approx. 30 g;
with adaptor board 99 x 41 x 12 mm, approx. 50 g
Power supply 12 ... 24 V DC ±10 %, < 60 mA, not galvanically isolated
Available accesoires
Adaptor board UA73.2 (RS485 / RS422) or
Adaptor board UA77.1 (inkl. converter RS422/RS232)
EMC OIML R-76:2006 and DIN EN 45 501:1992/AC1993