PawExact

Problem guide · evidence separated

Dust and sensor behavior

Dust and sensor behavior are separate observations. Current official guidance specifically warns that some light or translucent litter can affect level or drawer readings.

Start here

Official boundaries related to this issue

These statements are included only when they directly concern the failure mode. They do not name every SKU shown below.

OfficialLitter-Robot 4
“Some silica gel litter beads and crystals can also be used with Litter-Robot, as long as they pass through the screen. However, translucent or white-colored litter (most often seen in crystal litter) may impact the litter level and Drawer Full Indicator (DFI) accuracy in Litter-Robot 4 and are therefore not recommended.”
Official source
OfficialLitter-Robot 5
“Some silica gel litter beads and crystals can also be used with Litter-Robot, as long as they pass through the screen. However, translucent or white-colored litter (most often seen in crystal litter) may impact the litter level and Drawer Full Indicator (DFI) accuracy in Litter-Robot 5 and are therefore not recommended.”
Official source

Use the signal carefully

Treat dust and sensor readings as two investigations

Dust may require cleaning, while a level-reading error may involve litter color, transparency, fill height, lighting, firmware, or sensor condition. One observation does not prove which mechanism is responsible.

  1. Check 1Compare the physical litter and drawer levels with the app reading before assuming a sensor failure.
  2. Check 2Record whether the product is light-colored or translucent and whether the mismatch changes after maker-recommended sensor cleaning.
  3. Check 3If the reading remains unreliable, keep the product-level result conditional instead of treating successful cycling as complete compatibility.

Observation language

Record the observation before naming the cause

Use concrete, repeatable descriptions. Each line below separates what can be seen from conditions that must stay separate and conclusions the observation cannot support.

  1. 01Event timing

    Fine residue appears after pouring or after cycling

    Observable
    A fine layer is first noticed immediately after topping up, or only after later machine cycles, with the interval and surface photographed separately.
    Record separately
    Keep pour amount, cycle count, cleaning date, product color, physical fill, and the app's bed and drawer readings as separate observations.
    Cannot infer
    A visible timing pattern does not measure airborne dust or prove that residue caused a sensor mismatch; light or translucent litter remains an independent official reading concern.
    Comparable when
    Use the same surface and inspection interval before and after one documented action; do not change formula, cleaning, and calibration together.
  2. 02Dust signal

    Fine residue appears on machine surfaces

    Observable
    A fine, wipeable layer is visible on a known surface or sensor area after a recorded interval, separate from larger grains and fragments.
    Record separately
    Record location, interval, cleaning state, pour event, cycle count, and whether the residue was airborne or only settled.
    Cannot infer
    Visible residue does not provide a concentration, health conclusion, or proof that it caused a reading error.
    Comparable when
    Use the same surface and interval for comparison, and do not combine settled dust with particles produced by a broken clump.
  3. 03Bed reading

    The app level differs from the physical bed

    Observable
    The litter surface can be checked against the physical fill boundary while the displayed level reports a different state.
    Record separately
    Record physical leveling, litter color or transparency, cleaning, calibration, firmware context, and any Hopper setup independently.
    Cannot infer
    A mismatch does not prove that dust is the cause, and successful cycling does not prove that the level reading is reliable.
    Comparable when
    Recheck the unchanged litter after maker-directed cleaning or calibration before assigning the change to the product.
  4. 04Drawer reading

    The displayed drawer state differs from inspection

    Observable
    The waste drawer can be physically inspected and photographed while the app or machine indicates a different fullness state.
    Record separately
    Keep actual drawer contents, liner placement, light-colored or translucent material, cleaning state, and recent emptying as separate fields.
    Cannot infer
    The mismatch alone does not identify litter, liner placement, residue, firmware, or a sensor fault as the cause.
    Comparable when
    Compare the physical and displayed states at the same time instead of relying on a later memory of drawer fullness.
  5. 05Change test

    The reading changes after maintenance without a litter change

    Observable
    Cleaning, leveling, emptying, or recalibration is followed by a different displayed state while the exact litter remains the same.
    Record separately
    Record which maintenance step occurred and avoid grouping several steps into one undocumented fix.
    Cannot infer
    A corrected reading does not prove the litter had no effect; it shows that a non-product variable changed the observed state.
    Comparable when
    Stop making an exact-product causal claim when the result changes without changing the product.

Continue by model or mechanism

Use the route that matches your observation

These links narrow a broad symptom into a machine-specific or mechanism-specific check. They do not turn a report into a universal fix.

Exact-pair signals

Reports that explicitly mention the issue

Absence from this list means “not recorded in the selected reports,” not “problem-free.”

Single reportLevel Error

Original Health Monitoring Litter

PrettyLitter · Litter-Robot 4

After roughly four months the author said the original non-clumping PrettyLitter worked almost perfectly in LR4, but the app always read the litter as low; a 2026 update says the combination still works well.

Original source
Original public text was readable when reviewed
Use mode
Standalone versus mixture not stated
Accessory
Unknown
Use duration
1240 days
Open full context Original report
Single reportDust

Original Health Monitoring Litter

PrettyLitter · Litter-Robot 4

A two-cat household reports more than a year of original PrettyLitter use in LR3 and LR4 with good odor control and low tracking, but dust and saturation require regular replacement and cleaning.

Original source
Original public text was readable when reviewed
Use mode
Standalone versus mixture not stated
Accessory
Unknown
Use duration
365 days
Open full context Original report
Single reportDust

Original Health Monitoring Litter

PrettyLitter · Litter-Robot 4

The author says original PrettyLitter works well in LR4 with a seven-minute delay and does not stick, while failed cycles can leave pooled urine and dust still requires sensor and interior cleaning.

Original source
Original public text was readable when reviewed
Use mode
Standalone versus mixture not stated
Accessory
Unknown
Use duration
Unknown; qualitative wording is not converted to days
Open full context Original report

Known limit

What this page cannot prove

The current records do not establish a dust threshold or prove causation for a sensor error. Firmware, cleaning, fill level, lighting, and litter appearance may all matter.