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Apera PION400-K portable pH/potassium ion meter with IndSen electrode
Apera PION400 in pH mode with 201T-S pH electrode
Apera PION400-K kit in carrying case with electrodes, buffers, K+ standards and TISAB-D
Apera IndSen 2071M-K-TS potassium ion-selective electrode
Apera TISAB-D ionic strength adjustment buffer
Apera PION400-K portable pH/potassium ion meter with IndSen electrode
Apera PION400 in pH mode with 201T-S pH electrode
Apera PION400-K kit in carrying case with electrodes, buffers, K+ standards and TISAB-D
Apera IndSen 2071M-K-TS potassium ion-selective electrode
Apera TISAB-D ionic strength adjustment buffer

Apera Instruments PION400-K Portable pH/Potassium Ion Meter Kit

$930.00

    pH and potassium in one IP57 handheld kit, with both electrodes and all standards in the case.

    • IndSen 2071M-K-TS ISE: 0.039–39,000 mg/L (ppm)
    • 201T-S pH electrode with pH 4.00/7.00/10.01 buffers
    • Four K⁺ standards plus TISAB-D
    • Automatic electrode recognition; four AA batteries

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APERA INSTRUMENTS / PION400-K / AI4364

Potassium and pH in the field.
Two electrodes, one case.

The PION400-K measures potassium ion (K⁺) concentration directly in aqueous samples with Apera’s IndSen 2071M-K-TS combination electrode, which has a built-in temperature sensor. The electrode covers 0.039 to 39,000 mg/L (10⁻⁶ to 1 mol/L), and the meter reads in pX, mol/L, ppm or mg/L, with mV and temperature.

As a PION400 kit it also measures pH, with the 201T-S pH/temperature electrode and pH 4.00, 7.00 and 10.01 buffers in the case. The kit includes four K⁺ calibration standards and TISAB-D ionic strength adjuster. The meter recognizes the electrode automatically, is IP57 rated and runs on four AA batteries.

Apera PION400 portable pH/ion meter with ion-selective electrode
PION400 meter with the IndSen electrode. The displayed reading is illustrative, not a sample result.
Choose your ion meter kitClick or tap to compare 4 kitsChoose an item below - click or tap here to close

Pick the ion first, then decide whether you also need pH. ION400 kits measure ion, mV and temperature; PION400 kits add pH with a second electrode. Each card opens that product page.

Know what arrives
in the carrying case.

Included item Order contents
PION400 pH/ion meter Handheld IP57 meter, four AA batteries.
201T-S pH electrode pH/temperature electrode.
pH buffer solutions pH 4.00, 7.00 and 10.01, 50 mL each.
IndSen 2071M-K-TS electrode Combination potassium ion-selective electrode with built-in temperature sensor, 1 m cable.
1000 ppm K⁺ standard 100 mL.
K⁺ calibration standards 1, 10 and 100 ppm, 50 mL each.
TISAB-D Total ionic strength adjustment buffer, 50 mL.
Carrying case Apera lists it at 360 × 275 × 80 mm.
User manual PION400-K operation and calibration.

Kit list follows Apera’s PION400-K product page.

Apera PION400-K kit in its carrying case with meter, electrodes, standards and TISAB-D
PION400 kit as shipped: meter, electrodes, calibration standards and TISAB-D in the foam-lined case.
Apera IndSen 2071M-K-TS combination potassium ion-selective electrode
IndSen 2071M combination ion-selective electrode with built-in temperature sensor and 8-pin connector.

Store it dry.
Condition it before use.

The IndSen electrode uses an ultra-firm PVC membrane with a solid, non-volatile electrolyte; Apera states this gives two to three times the life of an ordinary PVC electrode. The reference is double-junction with a silver-ion-free gel, the housing is 16 mm and IP67 rated, and a 30 kΩ NTC thermistor in the body feeds automatic temperature compensation.

It can be stored dry. Before measuring, soak it 5 to 10 minutes to pre-condition. Apera rates it at 90% response in 10 seconds and a stable reading about 2 minutes after immersion, with a slope of 54 ± 5 mV at 25°C, an operating range of 5–50°C and sample pH of 1.0–9.

Calibrate, then read in the unit you need.

Calibrate with the kit standards

The meter supports one- to three-point calibration with guided prompts and shows the electrode slope afterwards. The kit’s 1, 10 and 100 ppm K⁺ standards cover three points; choose the points that bracket your samples.

Self-diagnosis

The meter flags calibration solution errors and aging electrodes, and displays the slope so you can judge electrode condition before measuring.

Fifteen ions preset

Besides K⁺ and NH₄⁺, the meter is preconfigured for Ca²⁺, NO₃⁻, Cu²⁺, F⁻, Na⁺, Cl⁻, Br⁻, I⁻, Ag⁺, S²⁻, Pb²⁺, Cd²⁺ and Hg²⁺, plus user-defined “Ion X” settings, so it can run other Apera ion-selective electrodes.

Adjust ionic strength.
Treat standards and samples alike.

TISAB-D is Apera’s total ionic strength adjustment buffer for its potassium and ammonium electrodes. Add it in the same proportion to the calibration standards and to every sample so the electrode sees the same ionic background in both.

Keep samples within the electrode’s pH range of 1.0 to 9 and its operating range of 5–50°C. The 1000 ppm K⁺ standard is the highest point in the kit; the electrode itself reads up to 39,000 mg/L.

Apera TISAB-D total ionic strength adjustment buffer for potassium and ammonium electrodes
TISAB-D, shown in Apera’s 250 mL retail bottle. The kit includes 50 mL.
Apera PION400 meter in pH mode with 201T-S pH electrode
PION400 in pH mode with the 201T-S electrode. The displayed reading is illustrative.

Switch to pH with the second electrode.

Connect the 201T-S pH/temperature electrode and the PION400 recognizes it and moves to pH mode. It reads 0 to 14.00 pH at 0.01 resolution, ±0.01 pH ±1 digit, with one- to three-point automatic calibration and temperature compensation from 0 to 100°C, automatic or manual.

The kit includes pH 4.00, 7.00 and 10.01 buffers, 50 mL each. The meter switches between pH, ion and mV modes, so one handheld covers both measurements.

Check the specifications.

pH reads 0–14.00 at ±0.01 pH ±1 digit. Ion concentration reads 0.00–10.00 pX at 0.01 pX resolution, ±1.0% F.S ±1 digit; mV reads −1000 to 1000 mV, ±0.2% F.S ±1 digit; temperature reads 0–100°C at 0.1°C, ±0.5°C ±1 digit.

The meter measures 86 × 196 × 33 mm, weighs 331 g, runs on four AA batteries and is IP57 rated against dust and water. The IndSen 2071M-K-TS covers 0.039–39,000 mg/L (ppm); 10⁻⁶ to 1 mol/L, with a 1 m cable and 8-pin connector.

Compare the other 400 Series ion kits.

The same meter platform comes as ION400-K (AI4356), ION400-NH (AI4325) and PION400-NH (AI4333). ION400 kits measure ion, mV and temperature; PION400 kits add pH with the 201T-S electrode and buffers. Choose by the ion you report and whether you also need pH from the same handheld.

PION400-K buyer questions

What does the PION400-K measure?

pH, potassium ion concentration, mV and temperature. Ion results display in pX, mol/L, ppm or mg/L.

What is the potassium measuring range?

The IndSen 2071M-K-TS electrode covers 0.039–39,000 mg/L (ppm); 10⁻⁶ to 1 mol/L.

Does the electrode need to be stored wet?

No. Apera states it can be stored dry. Soak it 5 to 10 minutes to pre-condition before measuring.

Which standards come in the kit?

1, 10 and 100 ppm K⁺ standards (50 mL each), a 1000 ppm K⁺ standard (100 mL) and 50 mL of TISAB-D. The PION400 kit adds pH 4.00, 7.00 and 10.01 buffers.

Can the meter run other ion electrodes?

Yes. It is preconfigured for 15 ions and accepts user-defined “Ion X” settings, with automatic electrode recognition.

Is there a manual online?

Apera ships the instruction manual in the kit but does not publish it online. Contact us and we will request a copy.

What warranty applies?

Apera’s limited warranty covers the meter for three years and the probes for six months from delivery, excluding accidental damage, improper use, normal wear and the other causes in Apera’s terms. Warranty service is handled through Apera; returns are coordinated with Blue Tiger Scientific.

Confirm the exact configuration before ordering.

Review PION400-K AI4364 against the ion and range you report, and the standards you will keep on hand. Return to the live price and ordering controls when the configuration fits your work.

Back to price and ordering ↑
    SpecificationDetail
    Model / manufacturer catalogPION400-K / AI4364
    ParameterspH, potassium ion, mV, temperature
    pH range / resolution / accuracy0–14.00 pH / 0.01 pH / ±0.01 pH ±1 digit
    pH calibration / temperature compensation1–3 points, automatic / 0–100°C, automatic or manual
    Ion range / resolution / accuracy0.00–10.00 pX / 0.01 pX / ±1.0% F.S ±1 digit
    Ion unitspX, mol/L, ppm, mg/L
    mV range / resolution / accuracy−1000 to 1000 mV / 1 mV / ±0.2% F.S ±1 digit
    Temperature range / resolution / accuracy0–100°C (32–212°F) / 0.1°C / ±0.5°C ±1 digit
    Preset ions15 (Ca²⁺, NH₄⁺, NO₃⁻, Cu²⁺, F⁻, K⁺, Na⁺, Cl⁻, Br⁻, I⁻, Ag⁺, S²⁻, Pb²⁺, Cd²⁺, Hg²⁺) plus user-defined Ion X
    ElectrodeIndSen 2071M-K-TS combination potassium ISE with 30 kΩ NTC temperature sensor
    Electrode measuring range0.039–39,000 mg/L (ppm); 10⁻⁶ to 1 mol/L
    Electrode slope / response54 ± 5 mV at 25°C / 90% in 10 s; stable about 2 min after immersion
    Electrode operating temperature / sample pH5–50°C / 1.0–9
    Electrode resistance / stability2–10 MΩ / < 8 mV per 24 h (< 1000 ppm)
    Electrode referenceDouble junction; Ref. I 0.1 mol/L CH₃COOLi gel, Ref. II 3.5 mol/L KCl gel
    Electrode body / cable / connectorTip Ø16 × 120 mm, cap Ø20 × 65 mm, IP67 / 1 m / 8-pin
    Power4 × AA (1.5 V)
    Meter protectionIP57
    Meter dimensions / weight86 × 196 × 33 mm / 331 g
    Carrying case360 × 275 × 80 mm
    Manufacturer limited warrantyThree years for the meter, six months for probes, from delivery; exclusions apply

    Ordering Information

    Ordering detailConfiguration
    Manufacturer catalogAI4364
    Blue Tiger SKUBTS-AI4364
    Order unit1 PION400-K meter kit
    Order contentsPION400 pH/ion meter; 201T-S pH/temperature electrode; pH buffers 4.00, 7.00 and 10.01 (50 mL each); IndSen 2071M-K-TS electrode; 1000 ppm K⁺ standard (100 mL); 1, 10 and 100 ppm K⁺ standards (50 mL each); TISAB-D (50 mL); carrying case; user manual
    Replacement electrode and bufferIndSen 2071M-K-TS electrode; TISAB-D (250 mL); 201T-S pH electrode (AI1312)

    Warranty Information

    APERA INSTRUMENTS, LLC warrants this instrument to be free from defects in material and workmanship and agree to repair or replace free of charge, at the option of APERA INSTRUMENTS, LLC, any malfunctioned or damaged product attributable to the responsibility of APERA INSTRUMENTS, LLC for a period of THREE YEARS for the instrument (SIX MONTHS for the probes) from the delivery.

    This limited warranty does NOT cover any issues due to:

    • Accidental damage
    • Improper use
    • Normal wear and tear
    • Transportation
    • Storage
    • Failure to follow the product instructions
    • Unauthorized maintenance, modifications, combination or use with any products, materials, processes, systems or other matter
    • Unauthorized repair
    • External causes such as accidents, abuse, or other actions or events beyond our reasonable control.

    PION400-K documents

    The PION400-K instruction manual ships printed in the kit; Apera does not publish it online. For a copy before you order, or help with setup and calibration, contact Blue Tiger Scientific and we will request it from Apera.

Questions about a product? Ask us here.

email us here: info@bluetigerscientific.com or live chat

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