Shandong Pengcheng Max Engineering Machinery Co., Ltd.\u00a0 is not a trading office with a showroom. It builds complete machines. The company moved into Rushan, on the Weihai coast, in 2023, and in 2024 broke ground on a 349-mu manufacturing base \u2014 a \u00a51.4 billion investment covering 147,000 m\u00b2 of floor area and four production workshops. It is the first complete-machine engineering machinery base in Weihai. Three of the four workshops are already in production. More than 90% of what leaves the line is exported.<\/p>\n That export ratio is what decided the nature of this retrofit. A machine delivered to an overseas buyer has to travel with a safety package the buyer can actually check: a calibration certificate, the rated capacity chart the controller is actually running, and manuals in the operator’s language. None of those can be added by after-sales. They are installed and documented at the assembly stage, or not at all.<\/p>\n The unit on the line that week was a 50-tonne-class hydraulic material handler \u2014 long boom, grab attachment, the frame that works scrap yards, steel mills and bulk terminals. Its normal state is continuous duty, not the occasional lift.<\/p>\n A truck crane is a solved problem. Its rated capacity chart is a lookup table: boom length \u00d7 radius \u2192 maximum load. The operator reads the chart, picks a configuration, and the rest is execution.<\/p>\n A material handler differs in three ways:<\/p>\n Regulators treat overload protection as mandatory equipment rather than an option. The ISO 10245<\/a> series (cranes \u2014 load limiting and indicating devices), China’s GB\/T 12602<\/a>, y EN 13000<\/a> for mobile cranes all describe the same thing: what a material handler load moment indicator must detect,, and how it must respond. For a machine heading overseas, that paperwork travels with the machine.<\/p>\n System model SZ-EM02, SeeZol’s\u00a0hydraulic material handler load indicator<\/a>. The same sensing chain also ships as a material handler weighing system: the hardware that protects the machine is the hardware that bills the load. That overlap is deliberate, and it shapes how we specify the product line.<\/p>\n The sensor figures are listed together, because they set the ceiling for the whole chain:<\/p>\n One number deserves explaining, because quotation sheets often blur it. The pressure sensor’s 0.5% F.S. looks far better than the \u00b13% system figure \u2014 and it is. The sensor is not the weak link. The \u00b13% is what survives the whole chain: pressure, geometry, algorithm, display. On a 50-tonne machine that is \u00b11.5 t.<\/p>\n The boom sensor SZ-A01BM reports luffing angle. Material handler booms are long and the geometry near the extreme radii is non-linear \u2014 which is exactly why calibration points cannot be skipped.<\/p>\n The stick sensor SZ-A01AM reports stick articulation. The grab is mounted at the end of the stick, so the stick angle sets the grab’s horizontal distance from the machine \u2014 its effective radius. Body, boom and stick angles together are what let the controller know where the grab actually is in space. All three come off the same SZ-A01 measuring platform; only the mounting position differs.<\/p>\n This 50-tonne machine runs two SZ-P201S pressure sensors: one teed into the lift cylinder’s supply line \u2014 the primary signal for lift force, mapped to host channel P1 \u2014 and one into the return line (P2) for cross-check and redundancy. Sampling both is what gives the controller’s estimate its safety margin. Both follow the rule below. SeeZol pressure sensors ship with a standardised \u00bc-inch interface, which reduces the field work to bridging the sensor’s \u00bc end to the machine’s hydraulic end. How that bridge is built depends on how the machine’s pipework is joined, and there are three documented methods: a tee at an existing threaded joint, a flange at a clamp or quick-coupler joint, or screwing straight into the main test port on the machine’s burst (balance) valve. Which one applies is decided by the machine, not by the catalogue.<\/p>\n Three rules govern the routing: corrugated conduit over the whole length; run along the machine’s existing hydraulic channels and fixings, which keeps it neat and mechanically secure; and leave appropriate slack where boom movement stretches the hoses, so the signal cable is never pulled tight or snapped.<\/p>\n Wiring the machine is the first step. Calibration is what gives a material handler load moment indicator its judgement.<\/p>\n On accuracy, stated completely: this machine runs at \u00b13% system error. Its job is overload warning and limiting, not trade-level metering. If grab weights are going onto an invoice, the accuracy budget and the calibration interval both change. Those are two different acceptance criteria, and which one you need should be settled at selection stage, not after delivery.<\/p>\n Exporting more than 90% of output means every machine delivered carries the same safety package. The value of the first unit is not that it was fitted \u2014 it is that sensor positions, bracket drawings, cable routing and calibration records become a template. After that it is a production management problem, not an engineering one.<\/p>\n It is the same path our previous project on this machine class took:\u00a0the 300-ton port transfer material handler at Huanghai Machinery<\/a>. That machine was a different order of scale entirely \u2014 boom pivot close to 10 m above ground, sensor points above 10 m \u2014 but the sequence was identical: site survey, structural evaluation, position selection, installation, stepped calibration, acceptance. Once the LMI is in, the next step is usually the weighing system and the data platform: from single-point safety protection to whole-machine digital management.<\/p>\n Yes. Calibration needs known test loads applied in steps across several radii. This machine was calibrated at the assembly stage, and the calibration record ships with the machine’s documentation. Machines already in service need a window carved out of production instead.<\/p>\n Not quite. An LMI continuously displays the measured moment against the rated capacity chart; a load limiter focuses on intercepting dangerous movement at a set threshold. SeeZol’s current controller combines both \u2014\u00a0this comparison<\/a>\u00a0covers the difference in detail.<\/p>\n It depends on the structure. This 50-tonne machine runs a complete set: three angle sensors \u2014 body SZ-A01BD, boom SZ-A01BM and stick SZ-A01AM \u2014 plus two SZ-P201S pressure sensors, one on the lift cylinder’s supply line (channel P1) and one on the return line (P2), five in total. Whether another model gains or loses a sensor comes down to boom sections and whether the hydraulic circuit has dual test ports \u2014 set by structure, not by tonnage class.<\/p>\n Sensors fail before controllers do. So a fair question before signing is the lead time and price of a spare angle sensor and pressure sensor. If the answer is “we’ll check”, check the next supplier.<\/p>\n Working temperature is \u221220 \u00b0C to +70 \u00b0C, with an IP65 warning and display unit and IP67 sensor bodies. Rushan is a coastal base, so humidity and salt spray are the normal condition \u2014 check protection ratings against that environment, not against an inland workshop.<\/p>\n<\/div>\n Send us your machine details and get a configuration proposal within one business day.<\/b><\/p>\n What we need: machine model, rated capacity or grab weight, typical working radius, and the working environment (scrap yard, steel mill, terminal, cold store, coastal). We will come back with the sensing chain, mounting positions and a calibration plan \u2014 not just a model number.\u00a0Contact us \u2192<\/a><\/p>\n<\/div>\n![\"50-ton](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/01-machine-overview.jpg\")
1. The customer and the machine<\/h2>\n
2. Why a grab machine is a harder LMI problem than a crane<\/h2>\n
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![\"Load](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/13-sensor-layout-diagram.jpg\")
3. What we fitted: the SZ-EM02 material handler load moment indicator<\/h2>\n
![\"SeeZol](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/11-component-set.jpg\")
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\n Working voltage<\/th>\n 12-36 V CC<\/td>\n<\/tr>\n \n Working \/ storage temperature<\/th>\n \u221220 \u00b0C to +70 \u00b0C<\/td>\n<\/tr>\n \n System error<\/th>\n \u00b13%<\/td>\n<\/tr>\n \n Display error<\/th>\n \u00b13%<\/td>\n<\/tr>\n \n Relay contact capacity<\/th>\n AC 220 V \/ 3 A<\/td>\n<\/tr>\n \n Protection level<\/th>\n IP65<\/td>\n<\/tr>\n \n Displayed values<\/th>\n Load weight, working radius, height<\/td>\n<\/tr>\n \n Logging<\/th>\n Overload records, real-time grab-cycle weighing, per-customer and per-shift weight logs<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n \n
\n \nComponente<\/th>\n Model<\/th>\n Key figures \/ mounting<\/th>\n<\/tr>\n<\/thead>\n \n Angle sensor (body)<\/td>\n SZ-A01BD<\/td>\n Range \u00b110\u00b0 to \u00b190\u00b0, resolution 0.05\u00b0, absolute accuracy 0.1\u00b0, response 0.02 s, 9\u201336 V DC, IP67; welded to upper structure<\/td>\n<\/tr>\n \n Angle sensor (boom)<\/td>\n SZ-A01BM<\/td>\n Same measuring platform; current, voltage, RS232 or RS485 output; welded to boom side<\/td>\n<\/tr>\n \n Angle sensor (stick)<\/td>\n SZ-A01AM<\/td>\n Same measuring platform; current, voltage, RS232 or RS485 output; welded to stick side<\/td>\n<\/tr>\n \n Hydraulic pressure sensor \u00d72 (supply line P1 \/ return line P2)<\/td>\n SZ-P201S (0\u2013400 bar)<\/td>\n 4\u201320 mA output, 0.5% F.S. accuracy, absolute accuracy 0.1 bar, 12\u201330 V DC, response 0.02 s, IP67; teed into lift cylinder test ports<\/td>\n<\/tr>\n \n Unidad de adquisici\u00f3n de datos y control<\/td>\n Safety monitoring host<\/td>\n CANopen bus, pressure channels P1\/P2, three angle inputs, relay outputs K1\u2013K3, RS485, USB logging<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n ![\"SZ-A01BD](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/12-angle-sensor-family.jpg\")
4. How a material handler load moment indicator is installed, sensor by sensor<\/h2>\n
4.1 Body attitude sensor \u2014 a weld-on bracket on the upper structure<\/h3>\n
![\"SeeZol](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/03-installer-on-platform.jpg\")
![\"SZ-A01BD](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/04-body-sensor-sz-a01bd.jpg\")
4.2 Boom and stick angle sensors \u2014 three angle sensors, three segments<\/h3>\n
![\"Boom](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/05-boom-angle-sensor.jpg\")
4.3 Pressure sensors \u00d72 \u2014 one on supply, one on return<\/h3>\n
![\"Hydraulic](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/06-pressure-sensor-tag.jpg\")
![\"Pressure](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/07-pressure-takeoff-bank.jpg\")
4.4 Cable routing \u2014 corrugated conduit, tied to the machine’s own lines<\/h3>\n
![\"Signal](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/08-hose-routing-bay.jpg\")
![\"Upper](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/09-upper-structure-pipework.jpg\")
![\"Boom](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/02-boom-pivot-structure.jpg\")
5. Commissioning<\/h2>\n
![\"Safety](\"http:\/\/127.0.0.1:53326\/static-html\/83a6fa4daa9b2d34\/images\/10-host-controller-unit.jpg\")
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6. Field notes: three things that decide whether the system is still switched on next year<\/h2>\n
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7. What the customer gets<\/h2>\n
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8. What this means for Pengcheng Max<\/h2>\n
9. Questions we get asked on site<\/h2>\n
Can a 50-tonne machine be calibrated indoors, at the factory?<\/q><\/p>\n
Is a material handler LMI the same as a load limiter?<\/q><\/p>\n
How many sensors does one machine need?<\/q><\/p>\n
Which part fails first?<\/q><\/p>\n
Does it work in cold or high-humidity environments?<\/q><\/p>\n