PololuPololu· Sensors

QTR-HD-31A Reflectance Sensor Array: 31-Channel, 4mm Pitch, Analog Output

Name: QTR-HD-31A Reflectance Sensor Array: 31-Channel, 4mm Pitch, Analog Output
Brand: Pololu
Price: 35.11 USD
Availability: InStock

Manufacturer part no. 4231

$35.11≈ 30.92 €

Price summary

Listed by Pololu at €30.92. Delivered to France, including shipping, VAT and any customs duty, it comes to about €67.10. Prices last checked on 2026-09-30.

Delivered cost is an estimate for a single item shipped to mainland France; the seller's checkout is authoritative.

In stock — 27 units

origin USA
RoHS3

View at seller ↗

Estimated landed cost

Landed cost breakdown
Item	€30.92
Shipping	€25.00
VAT (20%)	€11.18
Total delivered	€67.10

Estimate for a single item delivered to mainland France, shipped from outside the EU: customs duty and clearance fees may apply and are charged by the carrier.

Volume pricing

Qty	Unit price	Saving
≥ 1	$35.11
≥ 5	$32.30	−8 %
≥ 25	$29.72	−15 %

Datasheets & documents

Specifications (automatically extracted)

Electrical

Current	31 A
Voltage max.	5.5 V
Voltage min.	2.9 V

Mechanical

Weight

8.5 g

Other characteristics

Led current	30 mA
Maximum current draw	495 mA
Maximum range	50 mm
Optimal range	5 mm
Peak wavelength	940 nm
Sensor count	31
Sensor pitch	4 mm
Other pcb markings	0J11376
Output type	A (analog voltages)
Pcb dev codes	irs51a

Description

This array of IR LED/phototransistor pairs is great for precisely identifying changes in reflectance (like line detection). It operates from 2.9 V to 5.5 V and offers dimmable brightness control independent of the supply voltage and separate controls for the odd and even emitters. In general, the closer the object, the higher the contrast between light and dark readings, but high-reflectance objects are generally detectable out to around 50 mm. This version features the traditional-style QTR sensors without lenses.