RADWAG AS 220.R2 PLUS Manual, Explained: Setup, Leveling and Calibration

By MNM Scales · Last updated November 3, 2026

The RADWAG AS 220.R2 PLUS is a 220 g x 0.1 mg analytical balance with internal automatic adjustment, a glass draft chamber, a 100 mm pan and a 5.3 in backlit display. RADWAG writes one user manual for its whole R Series, so AS 220.R2 PLUS owners have to pick their steps out of shared chapters that also describe precision balances. If you searched for the AS 220 R2 PLUS manual, this is the plain-English version: the AS 220.R2 PLUS figures and procedures from that manual and the maker’s datasheet, with the display messages as the balance shows them.

AS 220.R2 PLUS manual at a glance: specifications

Item	AS 220.R2 PLUS
Capacity x readability	220 g x 0.1 mg
Verification unit (e) and minimum load	1 mg; 10 mg minimum load
Tare range	-220 g
Repeatability (standard deviation)	0.08 mg at Max; 0.07 mg at 5 percent of Max (permissible 0.1 mg and 0.09 mg)
Linearity	±0.2 mg
Minimum weight	USP: 140 mg; at 1 percent uncertainty (k=2): 14 mg
Stabilization time	2 seconds (FAST profile)
Adjustment	Internal, automatic; OIML accuracy Class I
Leveling and doors	Manual leveling with the level indicator at the front of the chamber; manual chamber doors
Pan and display	ø100 mm pan; 5.3 in backlit LCD
Interfaces	2 x RS-232, 2 x USB-A, USB-B; Wi-Fi module (not included)
Power	Adapter 100 to 240 V AC in, 12 V DC out; about 3 W
Operating range	10 to 40 °C (50 to 104 °F), 40 to 80 percent relative humidity
Protection and weight	IP43; balance about 7 kg (15.4 lb)

Unpacking and setting up the AS 220.R2 PLUS

1. Check the box: balance, weighing pan, pan shield, bottom insert (cover), centring ring and power supply. A printer, cables, the Wi-Fi module, a density kit, an anti-vibration table and calibration weights are not included unless ordered. Keep every piece of packaging; RADWAG asks for the original packaging for any shipment.
2. Pick the spot: a stable table or wall console free of vibration, drafts and dust, away from heat sources, at 10 to 40 °C and no more than 80 percent humidity, with a room temperature that changes slowly. Part of the balance is a strong magnet, so take care with magnetic samples.
3. Remove the transport lock: press it gently and turn it toward OPEN. Keep it; it goes back in whenever the balance is moved or shipped.
4. Fit the parts in order: bottom insert, centring ring (embossed side up), pan shield, then the weighing pan.
5. Level before power: turn the feet until the air bubble in the level indicator at the front of the weighing chamber is centered, with every foot resting firmly.
6. Ground and power it: to limit static, ground the housing with the bolt on the back. Connect only the supplied adapter. The display tests its segments, shows the program name and number, tests the internal adjustment weight mechanism and goes to zero.
7. Let it stabilize: a balance that was stored cold needs at least 8 hours plugged in to reach thermal stability (RADWAG’s figure for AS balances); readings can change during that time. Then run an internal adjustment, covered in the AS 220.R2 PLUS calibration section below.

Keys, menu and logging in

Key	What it does
ON/OFF	Switches the display on or off; the rest of the balance stays powered in stand-by
Zero and Tare	Zero sets precise zero; Tare stores a container weight (Net shows on the display)
Adjustment key	Starts an internal adjustment at once
Units key	Steps through the units you made available
Mode key	Picks a working mode such as counting, dosing or density
Database key	Opens the user, product and tare databases
Settings key	Opens the settings of the working mode you are in
PRINT/ENTER	Sends a reading to a printer or PC; confirms a menu choice
Menu and arrow keys	Open the main menu and move through it
F1 to F4	Function keys you can assign, for example to profiles, tare entry or log in

The main menu has nine groups: P1 Adjustment, P2 Working modes, P3 Communication, P4 Devices, P5 Printout, P6 Other (language, backlight, date, time, GLP autotest), P7 Info, P8 Units and, when a USB flash drive is plugged in, P9 Import/Export. Changes are saved when you return to weighing. To change protected settings and databases, log in as the administrator with the factory password listed in section 5.4 of the manual, then set up users and access levels (User, Advanced, Admin).

Weighing units on the AS 220.R2 PLUS

The balance weighs in grams by default and offers milligram and carat, plus pound, ounce, troy ounce, pennyweight, grain, momme, newton, tola, baht, tical and four tael units, depending on the configuration. In P8 Units, set each unit you use to YES under Accessibility, pick the Start unit the balance opens with, and define up to two custom units (u1 and u2) as a multiplier of the reading. The Units key then switches units while you weigh; parts counting and percent weighing keep their own displays. For paperwork conversions, use our grain to gram converter.

Weighing with 0.1 mg: good practice, profiles and filters

• Start the balance with an empty pan; at start-up the load has to be within about 10 percent of capacity.
• Before a series, exercise the pan a few times with a load near capacity (for example 200 g).
• Load gently and in the center of the pan, close the doors and read only when the stability marker shows.
• Zero works only within 2 percent of capacity (otherwise -Err2-), and the balance will not tare a negative value (-Err3-).
• Leave the balance plugged in between series and switch only the display off with ON/OFF.

Four weighing profiles tune the filters: Fast (active on first start), Fast dosing, Precision (slowest and most repeatable) and User. Only the User profile lets you change everything: filter from V.FAST to V.SLOW, value release (FAST, FAST+REL. or RELIABLE), autozero, last-digit display and the ambient setting STABLE or UNSTABLE. If a thermometer icon blinks on the display, the temperature inside the balance is still changing; wait for it to settle or run an adjustment. Working modes include parts counting, checkweighing, dosing, percent deviation, animal weighing, density of solids and liquids (density kit not included), statistics, totalizing, peak hold and pipette calibration.

AS 220.R2 PLUS calibration: internal adjustment, external weights and reports

RADWAG calls calibration “adjustment.” The manual asks for it before weighing begins, after long breaks between series and whenever the temperature inside an AS balance has moved by more than about 1 to 2 °C. The AS 220.R2 PLUS carries its own internal weight, so most adjustments need no external weight at all.

Automatic internal adjustment

• When the balance decides it needs an adjustment, it shows a thermometer or clock icon and Cal, gives you about 2 minutes to finish weighing, then counts down from CAL_30.
• Do nothing and it adjusts itself. Press Esc to finish your weighing first; it asks again in about 5 minutes. Putting it off for a long time lets temperature errors build up.
• On a non-verified balance, P1.5 Auto. calib. chooses the trigger: NONE, TEMP (temperature change), TIME (the interval in P1.6) or BOTH.

Manual internal adjustment

1. Close the doors and clear the pan.
2. Press the adjustment key (or open P1 Adjustment and choose P1.1 Int. calib.).
3. Leave the pan alone while DO NOT TURN OFF CALIBRATION shows; the balance saves the result and returns to weighing.

A load left on the pan stops the run with an error or RANGE EXCEEDED; remove it and start again. P1.4 Calib. test compares the internal weight against its factory value, and P6.11 GLP autotest places the internal weight 12 times (2 + 10), reports the error at Max and the repeatability as a standard deviation, and prints the report.

External and user adjustment

1. P1.2 Ext. calib. uses the factory-set external mass: at REMOVE MASS clear the pan and press ENTER; at PLACE MASS set the weight whose value the display shows and press ENTER.
2. P1.3 User calib. lets you enter your own weight value first. It has to be at least 30 percent of capacity, so 66 g or more on the AS 220.R2 PLUS; then follow the same REMOVE MASS and PLACE MASS steps.
3. On a verified (legal-for-trade) balance, the manual limits adjustment to the automatic and manual internal runs.

Every adjustment or test sends a report to COM1 (contents set in P5.1 Cal. report) for a printer or a PC file. Internal adjustment keeps the balance on track day to day; a calibration certificate still comes from checking it with external test weights. For a 0.1 mg balance, a 200 g weight such as our Rice Lake 200 g ASTM Class 1 weight (sold separately) covers a near-capacity check. Our calibration weight classes guide explains the classes, our internal vs external calibration guide explains when each matters, and our how often should a scale be calibrated guide helps set a schedule. We also stock calibration weights.

Connecting a printer, PC or USB flash drive

• Ports: COM1 for a printer, COM2 for an additional display or external buttons, USB-B for a computer and USB-A for a keyboard, a FAT-formatted flash drive or a USB printer. A USB-A port at the chamber front makes flash-drive exports easy. Unplug the balance from the mains before connecting or disconnecting anything.
• PC by USB: install the RADWAG USB virtual COM port driver from radwag.com, connect a USB A-B cable no longer than 1.8 m, note the new COM port in Device Manager and set P4.1 Computer port to USB.
• Straight into Excel: with the PC on USB, set the printer port to USB FREE LINK, choose the spreadsheet separator, set a delay of at least 2, put the cursor in a cell and press PRINT on a stable reading.
• Barcode scanners connect by RS-232 only; the Wi-Fi module (not included) allows remote control from Android, iOS or Windows devices.
• More on cables and drivers in our guide to connecting a scale to a computer by USB or RS-232.

Databases, ALIBI memory and GLP records

The AS 220.R2 PLUS keeps user, product, tare and weighing databases, and its ALIBI memory records up to 100,000 weighings so results can be traced later. Header, footer and GLP printouts can carry the balance ID, user, date and time. With a flash drive in the front USB port, P9 exports or imports databases, which makes it simple to copy products and users to a second balance.

Cleaning the weighing chamber

• Unplug the balance and its peripherals before you clean.
• Take the panes out instead of cleaning them in place: front frame and front pane, back frame and top pane, back pane, then the side panes; lift out the pan, pan shield and bottom insert.
• Use a dry flannel or lint-free cloth; a mild, non-abrasive cleaner is fine. For organic dirt on glass, use acetone first, then water or detergent; rinse with running water, then distilled water, and let the panes dry on a rack.
• Keep debris out of the pan opening, and refit the left and right panes on the correct sides.
• Our analytical balance preventive maintenance checklist turns this into a routine.

AS 220.R2 PLUS error messages

Display	Meaning	What to do
-Err2-	Value beyond the zero range (more than 2 percent of capacity)	Clear the pan and press Zero again
-Err3-	Value beyond the tare range (negative tare)	Zero the balance, then tare
-Err8-	Taring or zeroing took too long	Close the doors, stop drafts and vibration, and try again
-NULL-	Zero value from the converter	Restart with the pan parts seated; call us if it returns
-FULL-	Measurement range exceeded	Remove the load; stay under 220 g including the container
-LH-	Start mass error	Restart with an empty, correctly fitted pan; call us if it returns
Lo mass	Reading below -20 e on a verified balance	Press Zero
Blinking thermometer	Temperature inside the balance is changing	Wait for it to settle or run an internal adjustment

If an error keeps returning after a restart with an empty pan, send the balance to our repair bench. Other brands’ codes are in our scale error codes guide, and drifting readings in scale will not zero or keeps drifting.

AS 220.R2 PLUS vs other AS R2 PLUS models

Model (our listing)	Capacity x readability	Repeatability at Max	USP minimum weight	Pan
AS 60/220.R2 PLUS	60 g x 0.01 mg / 220 g x 0.1 mg	0.08 mg	20 mg	ø90 mm
AS 82/220.R2 PLUS	82 g x 0.01 mg / 220 g x 0.1 mg	0.08 mg	30 mg	ø90 mm
AS 220.R2 PLUS	220 g x 0.1 mg	0.08 mg	140 mg	ø100 mm
AS 310.R2 PLUS	310 g x 0.1 mg	0.12 mg	160 mg	ø100 mm
AS 520.R2 PLUS	520 g x 0.1 mg	0.25 mg	160 mg	ø100 mm

Pick the AS 220.R2 PLUS when 0.1 mg covers your smallest sample; step to a dual-range 60/220 or 82/220 model when you weigh below about 140 mg and need 0.01 mg. We also carry the AS 220.R1 PLUS with external calibration and the AS 220.X2 PLUS with a touchscreen; see all RADWAG analytical balances. For a wider comparison, read microbalance vs semi-micro vs analytical balance.

Selling by weight: choose the AS 220.R2 PLUS NTEP

RADWAG’s AS R2 PLUS series holds NTEP Certificate of Conformance 20-062, listed as Active on NCWM’s certificate search on November 1, 2026; it lists the AS 220.R2 PLUS as accuracy Class I with e = 0.001 g. Our standard AS 220.R2 PLUS listing is RADWAG’s laboratory version. For selling by weight, choose the NTEP Class I RADWAG AS 220.R2 PLUS NTEP (220 g x 0.1 mg). Our what is NTEP guide explains the approval, and our free legal-for-trade scale checker helps decide whether your use is trade.

Texas note: TDA does not require an NTEP certificate for every device, but the scale must meet NIST Handbook 44 and suit its use; some scales do need one, so we recommend NTEP models and can check yours. See TDA’s scales used in trade guidance (PDF) and our TDA scale certification guide, or call us or TDA to confirm your use.

Who uses the AS 220.R2 PLUS

• Pharmacies and compounding labs: weighing actives above the 140 mg USP minimum weight.
• QC and R&D labs: sample prep for HPLC and GC, formulation and density work in chemistry, food and cosmetics.
• Universities and schools: teaching and research labs that need 0.1 mg with GLP printouts.
• Cannabis and botanical processors: potency sample prep and in-house checks.

Setup tips from our technicians

• Our TDA-registered technicians put a 0.1 mg balance on a heavy, vibration-free surface; the RADWAG SAL/STONE/H anti-vibration table (sold separately) is built for it.
• Run an internal adjustment after the balance has stabilized and again whenever the thermometer icon appears.
• Pick the Precision profile, or set the User profile filter to SLOW, near an air vent instead of chasing a moving last digit.
• Let samples and containers reach room temperature; warm glassware creates air currents that read as mass.
• Handle test weights with gloves or tweezers so skin oil does not add mass.

Common mistakes we see

• Leaving the transport lock in, or throwing it away and shipping the balance without it.
• Fitting the centring ring upside down; the embossed side goes up.
• Weighing right after a cold delivery instead of allowing the full stabilization time.
• Pressing Esc at every CAL_30 countdown until the readings drift.
• Using a user-adjustment weight under 66 g, which is below 30 percent of capacity.
• Weighing samples lighter than the 140 mg USP minimum weight on a 0.1 mg balance.

Browse all RADWAG analytical balances.

Calibration, repair and rentals from MNM Scales

• Book calibration: the AS 220.R2 PLUS is in our up-to-2.2 kg tier: in-house calibration with a certificate is $95 and NIST calibration with a NIST-traceable certificate is $395. See our balance calibration service in Houston, all tiers on the scale calibration service page, and NIST vs in-house certificates.
• Mail-in calibration: lock the mechanism with the transport lock, remove the pan, pan shield, centring ring and bottom insert, and ship the balance in its original box with the mail-in calibration service.
• Cypress pickup by appointment: drop off or pick up at our Cypress, TX shop (21249 FM 529 Rd, Cypress, TX 77433).
• On-site service: on-site calibration is $295 plus $2 per mile, round trip, once per visit, plus the calibration fee for each balance. Our TDA-registered technicians bring certified test weights to pharmacies, QC labs, universities, cannabis and botanical processors and production lines across the Houston area.
• Repair: display, keypad, adapter and weighing-cell problems go to our scale repair bench.
• Rentals: we rent all types of scales; ask about a scale rental while yours is in for service.

Frequently asked questions

Where can I download the RADWAG AS 220.R2 PLUS manual?

RADWAG publishes the R Series user manual, which covers the AS 220.R2 PLUS, on its AS 220.R2 PLUS product page (direct PDF). This guide collects the AS 220.R2 PLUS steps and numbers from it.

How do I calibrate the RADWAG AS 220.R2 PLUS?

Let it stabilize, close the doors, clear the pan and press the adjustment key (or choose P1.1 Int. calib.). The balance places its internal weight, saves the result and returns to weighing. For an external check, use P1.2 Ext. calib. or P1.3 User calib. with a weight of 66 g or more.

What weight do I need to calibrate the AS 220.R2 PLUS externally?

User adjustment accepts any weight of at least 30 percent of capacity, so 66 g or more. A 200 g weight of a suitable class covers a near-capacity check on a 0.1 mg balance.

How do I level the AS 220.R2 PLUS?

Before plugging it in, turn the feet until the air bubble in the level indicator at the front of the weighing chamber is centered and every foot rests firmly on the table.

Why does the AS 220.R2 PLUS count down from CAL_30?

It has detected a temperature change or a set time interval and is about to adjust itself. Do nothing to let it run, or press Esc to finish weighing; it asks again in about 5 minutes.

How long should the AS 220.R2 PLUS warm up?

After cold storage, RADWAG asks for at least 8 hours plugged in before AS balances are thermally stable. Then run an internal adjustment.

Is the RADWAG AS 220.R2 PLUS NTEP approved?

The AS 220.R2 PLUS model is listed on NTEP CC 20-062 as accuracy Class I. For selling by weight, order the RADWAG AS 220.R2 PLUS NTEP version.

What is the minimum weight of the AS 220.R2 PLUS?

RADWAG gives a USP minimum weight of 140 mg and a minimum weight of 14 mg at 1 percent uncertainty (k=2), with a 10 mg minimum load.