Conveyor Belt Scale System
- General
1.1.Scope
1.1.1.This section describes the requirements for a conveyor belt scale system.
1.1.2.Under this item, the contractor shall furnish and install the conveyor belt scale system as indicated on the plans and as herein specified.
1.1.3.The conveyor belt scale system shall consist of 3 primary components, a scale integrator, a load sensor, and conveyor belt speed sensor.
1.2.Submittals
1.2.1.The following information shall be included in the submittal for this section:
1.2.1.1.Data sheets and catalog literature for the conveyor belt scale system
1.2.1.2.Interconnection and dimensional drawings.
1.2.1.3.Recommended Spare Parts
- Products
2.1.Conveyor Belt Scale Integrator
2.1.1.Power supply shall be selectable 115 or 230 Vac +-15% @ 60 Hz.
2.1.2.Accuracy shall be 0.1% of full scale
2.1.3.Resolution shall be 0.02% of full scale
2.1.4.Enclosure shall be suitable for indoor and outdoor use
2.1.5.Integrator shall be capable of operating within specifications in temperature ranges from -20 deg to 50 deg C (-5 deg to 122 deg F).
2.1.6.Enclosure shall be rated NEMA 4X, IP65
2.1.7.Integrator shall be programmable via local keypad or computer software
2.1.8.Display shall be illuminated dot matrix liquid crystal, 2 line display with 40 characters per line.
2.1.9.Firmware and Scale Parameters shall be stored in non-volatile field upgradable FLASH ROM
2.1.10.The integrator shall have a load cell input capable of 0 to 45 mV per cell
2.1.11.The integrator shall be capable of electronically balancing the load cell inputs
2.1.12.The integrator shall be able to accept 2 separate load cell inputs
2.1.13.The integrator shall have a speed sensor input capable of accepting a pulse train input 0 volts low, 5 to 15 volts high, with a frequency of 2 to 3000 Hz and an open collector switch and a dry contact closure.
2.1.14.The integrator shall have an input to accept a contact closure that will initiate an auto zero.
2.1.15.The integrator shall have 5 programmable discrete inputs capable of scrolling display readings, totalizer reset, initiating a zero calibration, initiating a span calibration, selecting a multispan, initiating a print, resetting a batch totalizer, and being used as an auxiliary speed input.
2.1.16.The integrator shall have an analog output programmable to 0 to 20 mA or 4 to 20 mA that can be programmed to correspond to rate, load, or speed.
2.1.17.The integrator shall have 2 contact closure remote totalizer outputs programmable to closure duration of 300 ms.
2.1.18.The integrator shall have 2 alarm/control programmable relay outputs. Each relay output shall have a form A SPST capable of 5 A at 250 Vac non inductive
2.1.19.The integrator shall have (2) RS-232 and (1) RS-485 communication outputs.
2.1.20.The integrator shall have an optional communications board capable of communicating Profibus DP, Profinet, Ethernet IP, or Device Net.
2.1.21.The scale integrator shall independently convert each loadcell input to a digital signal to be used by the microprocessor.
2.2.Conveyor Belt Scale Load Sensor
2.2.1.The load sensor shall have an accuracy of 0.5% over a 5 to 1 operating range with a single idler, 0.25% with a dual idler and 0.125% with three idlers.
2.2.2.The load sensor shall have a static beam that supports 2 loadcells for each idler supported by each of the 2 conveyor stringers.
2.2.3.The load sensor shall use 2 triple beam parallelogram type loadcells for each weigh idler.
2.2.4.The load sensor shall remove horizontal forces created by the belt moving through the scale area using a parallelogram loadcell design and shall not use pivots or check rods to remove these forces.
2.2.5.The load sensor shall use loadcells with a non-linearity on not more than 0.02% of rated output.
2.2.6.The load sensor shall use loadcells with a maximum hysteresis of not more than 0.02% of rated output.
2.2.7.The load sensor shall use loadcells repeatable to 0.01% of rated output.
2.2.8.The load sensor shall use loadcells rated for safe overload to 150% of rated capacity and an ultimate overload capacity of 300% of rated capacity.
2.2.9.The load sensor shall use loadcells that produce 2 mv/Vexc output at full scale.
2.2.10.The load sensor shall use loadcells with an operating temperature range of -40 deg to 75 deg C (-40 deg to 167 deg F) and shall be compensated from -18 deg to 65 deg C (0 deg to 150 deg F).
2.2.11.The load sensor shall use loadcells that are hermetically sealed.
2.2.12.The load sensor shall be capable of maintaining specified accuracies with belt speeds up to 5 m/sec (1000 Ft per Min).
2.2.13.The load sensor shall be capable of maintaining specified accuracies with idler diameters from 50 to 180 mm (2 to 7 inches).
2.2.14.The load sensor shall be capable of maintaining specified accuracies with conveyor inclines up to 20 deg.
2.2.15.The load sensor shall be capable of maintaining specified accuracies with idler spacing from 0.5 to 1.5 meter (1.5 to 5 feet).
2.3.Conveyor Belt Scale Speed Sensor
2.3.1.The belt speed sensor shall use a supply voltage of 10 to 30 V dc.
2.3.2.The belt speed sensor shall be capable of operating in a temperature range of -40 deg to 55 deg C (-40 to 131 deg F).
2.3.3.The belt speed sensor shall have a bi-directional input range of 0.5 to 470 rpm.
2.3.4.The belt speed sensor shall have a uni-directional open collector sinking output.
2.3.5.The belt speed sensor shall have an output of 10 to 30 Vdc pulse proportional to the speed sensor shaft rotation speed.
2.3.6.The belt speed sensor shall have an output of 32, 256, 1000 or 2000 pulses per revolution.
2.3.7.The belt speed sensor shall be capable of producing an output frequency of 2 to 3000 Hz. The belt speed sensor shall have an aluminum enclosure rated NEMA 4X, IP65.
- Operation
3.1.Conveyor Belt Scale Calibration
3.1.1.Scale calibration shall be accessible via a keypad on the front of the integrator, discreet inputs, or remote communications.
3.1.2.The scale shall have the ability to protect calibration through use of a security code.
3.1.3.The scale shall have the capability to initiate a zero calibration automatically
3.2.Conveyor Belt Scale Display
3.2.1.In the scales normal operation mode the display shall show the rate of material on the conveyor and a display of totalized material.