The platforms: how Advantus and Status read a urine strip
Describe how the Clinitek Advantus and the Clinitek Status/Status+ turn the colour of a reagent pad into a reported result, name the boards and assemblies on that path, and know which parts of each instrument are field-replaceable.
Two instruments, one principle
Both instruments in this course are reflectance photometers for urine reagent strips. A pad on the strip changes colour as it reacts with the urine; the instrument lights the pad, measures how much light comes back in several colour bands, compares it with a white reference read moments earlier, and converts the resulting percentage into a decode value and then into a clinical level such as negative, trace or 2+. Nothing is aspirated, nothing is pipetted and there is no fluidic path. Everything you learned in Level 1 about pumps, valves and tubing does not apply here; what applies is optics, mechanics that move a strip to a precise position, and a reference surface that must stay clean.
The Clinitek Advantus is a bench, semi-automated analyser for a laboratory that runs strips in a stream. The service guide we use (Advantus Service Guide, part 132410 Rev. A, 2006, issued under the Bayer HealthCare name before the business passed to Siemens) describes it as a scanning instrument capable of more than 500 strips an hour and as the successor of the Clinitek 500. The operator dips a strip, lays it on a platform, and the machine does the rest: it pushes the strip on, walks it under two readheads and drops it in a waste bin.
The Clinitek Status is a small, portable single-strip reader for clinics, wards and doctors' offices. It reads one strip or one immunoassay cassette (for example the hCG cassette) at a time on a test table that draws into the instrument. It runs from a mains adapter or from six AA cells. The Status service manual we have is a partial extraction, and it describes the original Status. The later Status+ keeps the same reading principle but adds features described on Siemens Healthineers' public pages, such as strip auto-checks and optional barcode and connectivity through the Clinitek Status Connect system. Where this course says Status, take it as the Status manual; check Status+ specifics against its own current documentation.
Advantus: strip transport
The strip path on the Advantus is a little conveyor built from parts the operator removes daily. At the left is the fixed platform with its load zone and a hold-down that keeps strips flat. A push bar sweeps a newly placed strip to the right onto the moving table. The moving table has fingers that rise, carry every strip one step to the right, and drop again. The drive housing under the platform turns one motor revolution into that lift-and-step motion. Three stepper motors do all the work: one for the push bar, one for the moving table and one for the readhead carrier. Each motor is driven from a controller IC on the MOTHER PCB.
Three optical interrupters tell the processor that the mechanics did what was asked: one confirms the fixed platform is seated, one confirms the push bar returned home, and one watches the moving table flag. The software expects each of them to change state within a set window in the cycle. If one does not, the instrument stops with a general error: 26 for the platform not in place, 24 for the push bar, 23 for the table. Remember that mapping; it is the first fork of most mechanical fault-finding in lesson 4.
A strip detector under the load zone decides that a strip has been laid down. It uses a row of red LEDs pulsed one at a time and photodetectors between them. Its detection thresholds are not fixed: the instrument learns them each time it is switched on, with no strip present and with the fixed platform in place, so that differences in LED output and table reflectance are cancelled. That has two practical consequences. Switching on with the platform out, or with a strip or a hand on the load zone, gives the detector wrong thresholds. And a change in room lighting after power-on can upset it until the next power cycle.
Advantus: readheads, calibration chip and the 7-second cycle
The Advantus has two identical readheads on one carrier that rides on a ball slide and is moved by its own stepper motor and belt. Each readhead has a lamp and a detector package with four broad filters: infrared, red, green and blue. Two readheads exist so that each strip is read twice, the guide giving roughly 25 and 67 seconds after dipping, which suits pads that develop at different speeds. Each detector channel feeds a two-stage Pre-AMP PCB; both Pre-AMPs feed one A/D PCB with an eight-channel converter, which also regulates the supplies for the Pre-AMPs and the lamps.
The cycle repeats every seven seconds. During it the readheads first find the white calibration chip on the fixed platform, take a dark reading with the lamps off, switch the lamps on and calibrate every channel on the white surface, then scan outward across the strip taking many readings, subtract the dark values and return to the chip. Reflectance is therefore always relative to the chip measured a second or two earlier. A dirty or scratched calibration surface does not just add noise: it changes the reference every pad is divided by, which is why lesson 3 treats cleaning the platform and calibration bars as a measurement task, not housekeeping.
The scan also checks the strip itself. Infrared reflectance in gaps between specific pads confirms that a strip is present and lying straight; the position of the strip tip against the calibration bar is measured and given a position number, with the middle value ideal. A strip too far out of position, skewed, upside down, dry or giving more than 100% reflectance is not reported but flagged with a data-set error against the readhead that saw it. You meet these as N–xx codes in lesson 4.
Advantus: electronics and interfaces
Two processors share the work. Processor 2 sits on the MOTHER PCB with an FPGA: it runs the motors, the strip detector and the sensors, reads the strip, does the reflectance and decode calculations, keeps the real-time clock and checks for hardware errors. Processor 1 sits on the MAIN PCB behind the touchscreen: it runs the user interface, converts decodes into clinical levels, handles the internal and external printers, the barcode and keyboard port and the host communication. A battery-backed memory keeps results and settings; the guide states room for about 200 control and 500 patient result sets. When the two processors stop talking, the customer sees an analyser error 56 with a sub-code.
The switching power supply accepts a wide mains range and produces plus and minus 5 V and plus and minus 12 V, distributed by the MOTHER PCB. Only the +5 V output is adjustable. The colour touchscreen is a resistive overlay on a passive LCD, driven from the MAIN PCB. Software lives in internal flash; an MMC program card in a slot behind the display is used only to load software and is removed afterwards. Rear connectors: a 9-pin RS-232 port, an Ethernet port provided by a small Ethernet-to-serial converter on the MOTHER PCB, a PS/2 socket for a keyboard or a wedge barcode reader (if it is a laser scanner, never look into its beam), and a 25-pin parallel port for an external printer. The internal printer is a thermal unit with its own small interface board.
The service policy is stated plainly: boards are not repaired at component level. Your replaceable units include the MAIN PCB, MOTHER PCB, power supply, A/D PCB, Pre-AMPs, lamps, strip detector, drive housing, table guides, crank arm, baseplate mechanism, printer, touchscreen, fan and the operator-removable platform parts.
Status and Status+: one strip, one image
The Status works differently. There is no scanning readhead. Six LEDs of different wavelengths light the whole read area through a plastic light guide; the reflected image goes via a mirror and a lens onto a CCD line array, so the entire strip or cassette is read in one exposure. Each read is repeated ten times and averaged. At the start of every test the instrument images the white calibration bar on the test table, which is its reference for that test. The table moves in and out on a small DC motor that engages moulded teeth on its underside; a shutter closes the opening behind it; a position sensor tells the processor where the table is. The table insert is double-sided: one face carries a channel for a strip, the other a seat for a cassette, and a cue mark at the channel end helps the instrument find the strip tip.
One main PCB carries a single microcontroller, flash for the program, static RAM, a serial EEPROM that holds setup and calibration data, a real-time clock backed by a coin lithium cell, the LED driver, a variable-gain amplifier for the CCD, the table motor driver, the printer drivers and an RS-232 interface. Software updates arrive on a specially formatted MMC card in a slot under the printer cover, or over the serial line. The display is a monochrome LCD with an 8 by 6 resistive touch matrix. The thermal printer is fed directly by the main board.
Field-replaceable units are few: test table, table insert, display and bezel assembly (which includes the power button), printer, main PCB and the optical chassis. The optical chassis carries the LEDs, light guide, mirror, lens, CCD, drive motor and gear, table sensor, connectors and battery tray. Everything inside it is aligned at the factory and there is no field alignment. If the optics or table drive fail, the chassis is replaced as a whole.
What this means for your first visit
Before you touch either instrument, write down the model, serial number, software version and, on the Advantus, print the setup or configuration report. On the Advantus, entering the service test mode or loading software returns the settings to factory defaults, so the printed report is your only record of the customer's ranges, ports, printer and strip settings. On the Status, setup lives in the EEPROM on the main PCB, so a main PCB change also means re-entering the customer's settings.
Then look at the strip type the laboratory uses and how the instrument is set for it, the reference surfaces, and the interface: printer only, serial host or network host through a connectivity product. Most calls on these instruments are solved in the first fifteen minutes by those three things: the right strip setting, a clean reference and a working data path.
| Part | What it does | How it fails | |
|---|---|---|---|
| 01 | Fixed platform with calibration bars and hold-down (A) | Load zone, flat strip path and the white reference read every cycle | Stained or scratched cal chip, worn hold-down, not seated: 26, 27, 29, 10-x errors |
| 02 | Push bar, moving table and drive housing (A) | Move each strip from load zone through both readheads to waste | Bent table pins, dry push-bar shaft, worn drive: 23, 24, 06-2, 08-x, 09-x |
| 03 | Strip detector PCB (A) | Senses a strip on the load zone; thresholds learned at power-on | False or missed detection, setup values out of range: 28, 31 |
| 04 | Readheads with lamps, Pre-AMP PCBs and A/D PCB (A) | Light the pads, detect four colour bands, digitise | Weak or dirty lamp, contaminated Pre-AMP, lost supply: 01–05, 25, 29, 30 |
| 05 | MOTHER PCB, processor 2 (A) | Motors, sensors, strip reading, calculations, ports and power distribution | No motion at power-up, port loop-back fails, 56-xx communication errors |
| 06 | MAIN PCB, processor 1, and touchscreen (A) | User interface, clinical levels, printers, host data, results memory | Blank or dead screen with good supplies, 21, 36, 37, 55 |
| 07 | Test table and insert with white calibration bar (S) | Carries strip or cassette; reference read at every test | Dirty or scratched bar, broken teeth: E11, E12, E58, E63–E65 |
| 08 | Optical chassis: LEDs, light guide, lens, CCD, motor (S) | Illuminates and images the whole read area; drives the table | LED or CCD failure, light ingress, misalignment: E12, E62, ECC codes |
| 09 | Main PCB with EEPROM, RTC cell and MMC slot (S) | Control, setup and calibration storage, printer and RS-232 | Checksum and memory errors E02–E04, E10, E20, E27 |
| 10 | Thermal printer (A and S) | Prints results and service reports | Wrong or reversed paper, dirty platen, lever up, loose flex: 50, E24, E28 |
Typical scenario: the Advantus that was 'recalibrated' with the platform out
Typical scenario, not a recorded case. A laboratory reports that its Clinitek Advantus sometimes pushes the bar across with nothing on the platform and sometimes ignores a strip. That morning the analyser had been switched on while the fixed platform was soaking in the cleaning tray, and the platform was refitted a few minutes later. The engineer explains that the strip detector learns its thresholds only at power-on and only correctly with the platform in place and the load zone empty. With the platform seated, the zone clear and a power cycle, detection becomes normal. The detector setup values printed from the service tests are within range.
On the Advantus the strip detector is calibrated at switch-on against the platform. Teach the laboratory to clean first, refit the platform, then switch on; and power-cycle with an empty load zone before you suspect the detector.
A urine analyser joined to the network on a tight access window
In an engineers' chat, a colleague was preparing to service a Sysmex urine analyser (model not recorded) at a site that allowed access only until midday. The task was to make the analyser visible as a network device and to set up how results were printed. Advice from others was practical: treat it like any other network device, agree the IP address, name and port with the site in advance, set printing options in the reporting software, and restart the device between jobs. No fault was involved; the case is about preparation. It is not a Clinitek case, but the same applies to any urine strip analyser sent to a host.
Data paths are part of the instrument. For an Advantus on Ethernet or a Status+ behind a connectivity product, collect the network parameters and the host contact before the visit, so the access window is spent on the instrument, not on finding the administrator.
On-site checklist
- Model (Advantus, Status or Status+), serial number and software version recorded
- Advantus: setup/configuration report printed before any service mode or software work
- Status: customer settings noted, because they live on the main PCB
- Strip type in use matched with the strip type set in the instrument
- Reference surfaces inspected: Advantus calibration bars on the fixed platform, Status white bar on the test table
- Data path identified: internal printer, external printer, serial host, network or connectivity product
- Power arrangement noted: Advantus mains; Status mains adapter or AA cells