Digital Panel Meter for Load Cell, Strain Gauge and Microvolt Applications

Load Cell & Microvolt Digital Panel Meter Frequently Asked Questions

Why does the meter sample internally at up to 60 times per second but only refresh the visible display 3.5 times per second?

This split is intentional — the fast internal Concurrent Slope conversion rate is specifically what enables reliable peak and valley capture of brief force excursions (such as the instant of failure in a tensile test), while the much slower display update rate keeps the visible reading legible for a human operator rather than an unreadable blur.

Can the moving average filter's 80 ms to 9.6 second time constants be changed without affecting the meter's underlying accuracy?

Yes — the filter is a display-smoothing choice applied after the underlying measurement is taken, and the Auto setting specifically selects an appropriate time constant based on the signal's actual noise characteristics, so filtering primarily trades responsiveness for display stability rather than changing the meter's fundamental measurement accuracy.

Does the volume-from-weight tank application require custom curve linearization for an irregularly shaped tank?

No — this is specifically documented as not requiring linearization, since weighing the tank directly captures its true total content regardless of the tank's internal shape; linearization would only become necessary if trying to infer volume indirectly from a level or pressure signal in an irregular tank, which is a different measurement approach than direct weight-based volume determination.

Can auto-tare and manual tare be combined, such as auto-taring an empty tank and later overriding with a manually entered value?

Both mechanisms are documented as available on the same meter, each suited to different practical situations — auto-tare captures whatever is currently on the scale as the offset via a pushbutton, while manual tare lets a known value (such as a rail car's stated empty weight) be entered directly; an installation can use whichever method fits the situation, including switching approaches between uses if the practical situation calls for it.

Why does span tempco use "% of reading" while zero tempco is expressed in microvolts per degree?

These describe two different kinds of temperature-driven error: span tempco (0.0015% of reading/°C) scales with the actual signal level, reflecting drift in the meter's gain or scale factor, while zero tempco (0.1 µV/°C) is a fixed baseline offset drift independent of signal level — expressing each in the units natural to its own error mechanism is what allows both to be combined correctly into an overall accuracy budget.

Does the analog output's ability to be transmitted via peak-recall apply to any parameter, or specifically to peak readings from tensile testing?

The documented tensile strength capture application specifically highlights peak transmission via RS232, RS485, USB, or Ethernet, but the meter's transmission capability generally isn't limited to peak values alone — the same communication paths carry whatever reading the meter is currently configured to output, with peak capture being one specific, well-suited use case for a destructive-testing application.

If I'm running four 350-ohm load cells in parallel off one meter's excitation output, does that leave any margin before hitting the 120 mA limit?

Each 350-ohm load cell at 10V draws roughly 28.6 mA, so four in parallel draw approximately 114.4 mA total — leaving only a small margin under the meter's rated 120 mA output, meaning an installation at or near this configuration should confirm actual load cell resistance and excitation voltage carefully rather than assuming generous headroom.

Does custom curve linearization for "lower-cost, less-linear load cells" mean any load cell's nonlinearity can be corrected regardless of severity?

The documented capability specifically supports up to 180 data points for spline-fit linearization, which can meaningfully improve accuracy for load cells with genuine, characterizable nonlinearity — but this assumes the nonlinearity is a stable, repeatable characteristic of the specific sensor that can be captured through calibration points, not a substitute for a load cell that's fundamentally unstable or has excessive hysteresis.

Does the Extended board's "rate derived from successive readings" have a specific documented use with load cells, or is it unrelated to weighing?

While rate-from-successive-readings is a general Extended-board capability documented across the Laureate product line (useful for tracking a changing signal's rate of change over time), its specific application to load cell signals would depend on the use case — such as tracking fill/drain rate on a weight signal — rather than being a dedicated, load-cell-specific feature separate from the board's general rate calculation capability.

Does the meter's 130 dB CMR and 90 dB NMR noise rejection matter more for load cell mode or microvolt mode?

Both modes benefit, but the practical impact differs — since microvolt mode measures absolute signals without the ratiometric excitation-referencing that load cell mode uses, noise coupled directly onto the signal path (addressed by NMR) or appearing between the signal and ground (addressed by CMR) has a proportionally larger effect on a genuinely tiny microvolt-level reading than on a load cell signal, which already benefits from ratiometric cancellation of excitation-related variation as an additional layer of noise immunity.

Load Cell Type Selection Questions From the Field

What's the fundamental difference between choosing a shear beam versus a single-point load cell for a platform scale?

Documented guidance specifically distinguishes these by application scale: single-point load cells are best suited for bench scales and small platforms, allowing off-center loading anywhere on the platform while maintaining accuracy, while shear beam load cells are documented as the workhorse choice for floor scales, tanks, and hoppers — generally larger installations than single-point cells are designed to handle.

When is an S-type load cell the right choice instead of a canister or shear beam design?

Documented selection guidance specifically ties S-type cells to in-line tension or compression applications where axial alignment can be maintained, such as crane scales, hopper scales, and tension-compression test machines — S-beams are documented as sensitive to off-axis or side loads, so applications with significant uncontrolled side loading are better served by shear beam or weighing-module designs instead.

Why are canister load cells specifically recommended for very high capacity applications like truck scales, despite being more complex to secure?

Documented guidance specifically notes canister (and double-ended shear beam) designs offer higher capacity per unit at extreme loads (above roughly 20,000 lb) compared to S-type cells — the tradeoff is that canisters are documented as more susceptible to twisting and toppling in truck scale applications specifically, which double-ended shear beams' rigid rectangular structure and dual fixed points are documented as better resisting.

Does load cell capacity selection follow a simple "bigger is safer" rule, or is oversizing actually a problem?

Documented guidance specifically warns against oversizing: choosing a load cell with enough capacity to handle the maximum expected load plus a safety margin is recommended, but an oversized load cell relative to the actual working load reduces measurement accuracy and resolution, since the sensor's full-scale range is being used only partially — undersized load cells, meanwhile, risk overload damage, so capacity selection is a genuine balance rather than simply choosing the largest available option.

Does NTEP certification matter for every load cell installation, or only specific ones?

Documented guidance specifically ties NTEP (or equivalent legal-for-trade) certification requirements to applications where the weighing result affects a commercial transaction — such as billing by weight — meaning it's a genuine requirement for legal-for-trade use but not necessarily relevant for purely internal process monitoring or quality control weighing that doesn't affect a trade transaction.

If I need to measure both tension and compression forces with the same load cell, does that narrow my options significantly?

Not necessarily — S-type load cells are specifically documented as versatile for both tension and compression in a single design, since force is applied through the center axis and the sensor's bending zone responds to force in either direction along that axis, making S-type a documented go-to choice specifically when both loading directions need to be measured by the same sensor.

Does load cell material (stainless steel vs. alloy steel) matter beyond just cost?

Yes — documented guidance specifically ties material choice to environmental exposure: stainless steel models are documented as resisting moisture, chemicals, and washdown conditions, making them suited to harsh or wet environments, while alloy steel is documented as appropriate for dry, indoor use where washdown or chemical exposure isn't a concern.

Beyond selecting the right load cell type, what installation factors can still degrade accuracy even with a well-chosen sensor?

Documented guidance specifically lists load introduction, mounting alignment, side-load control, temperature, vibration, moisture, EMI, grounding, and cable routing as factors that can compromise even a high-accuracy load cell's field performance — reinforcing that selecting the correct load cell type is a necessary but not sufficient condition for accurate results, since installation quality independently affects real-world accuracy.