A&D MX-50 Moisture Analyzer Manual: Setup, Programs and Calibration

This A&D MX-50 moisture analyzer manual guide covers setup, programs and calibration for the A&D MX-50 (51 g x 0.001 g, 0.01% resolution), on sale for $1,998.00 (regular $4,530.00), in stock.

The A&D MX-50 is a 51 g x 0.001 g halogen moisture analyzer that reads moisture to 0.01 percent. It dries a sample with a 400 W halogen lamp and works out moisture from the difference between the wet and dry weight, and its weighing sensor is the same Super Hybrid Sensor (SHS) design A&D uses in its analytical balances. A&D writes one instruction manual for four models, so MX-50 owners have to pick their numbers out of shared tables. Below are the MX-50 figures from that manual, with the display symbols exactly as the analyzer shows them. MNM Scales is an authorized A&D Weighing dealer.

MX-50 manual at a glance: specifications

Item	A&D MX-50
Sample weight range	0.1 g to 51 g
Minimum reading	0.001 g; moisture 0.01 or 0.1 percent
Repeatability (standard deviation)	0.02 percent with samples over 5 g; 0.1 percent with samples over 1 g (about 5 g of sodium tartrate dihydrate, standard mode MID., 160 °C, after pre-heating)
Heater	400 W halogen lamp; about 5000 hours lamp life
Drying temperature	50 to 200 °C (122 to 392 °F) in 1 °C steps
Heating patterns	Standard, ramp, step and quick drying
Analysis modes	Standard (5td), quick (quc), automatic (U-a), timer (U-t) and manual (U-m)
Result units	Moisture on a wet basis (factory setting), moisture on a dry basis (atro), dry content, ratio, grams
Program memory	20 programs (PROG 1 to 20)
Data memory	100 results
Interface	RS-232C; 2 m cable and WinCT-Moisture software included
Sample pan	ø85 mm; 20 reusable pans and 100 disposable aluminum foil pans included
Calibration	Weighing sensor with a 20 g or 50 g external mass; drying temperature with the AX-MX-43 certified temperature calibrator (not included)
Operating range	5 to 40 °C (41 to 104 °F), 85 percent relative humidity or less, no condensation; indoor use
Power	AC 100 to 120 V (3 A) or AC 200 to 240 V (1.5 A), 50 or 60 Hz, about 400 W
Size and weight	215 x 320 x 173 mm (8.46 x 12.60 x 6.81 in); about 6 kg

What comes in the box

The manual lists these standard accessories for the MX-50: pan support, breeze break ring, 20 sample pans, 2 pan handles, 100 disposable aluminum foil pans, glass fiber sheets, a 30 g sodium tartrate dihydrate test sample, spoon, tweezers, dust cover, display cover, power cord, spare fuses (T6.3A 250V and T100mA 250V), the RS-232C cable and the WinCT-Moisture CD-ROM. The 20 g calibration mass, the AX-MX-43 temperature calibrator and a printer are not included. Keep the packing box; A&D asks you to use it whenever the analyzer moves.

Setting up the MX-50

1. Pick the spot: a solid, level bench away from vibration, drafts, heaters, air conditioners and magnetic fields, in a room with enough ventilation for the hot air to clear. Keep anything flammable away and put nothing on the heater cover.
2. Level it: turn the leveling feet until the bubble in the spirit level is centered.
3. Check the voltage: read the voltage label on the back of the heater cover. A 100 to 120 V analyzer uses the 120 V halogen lamp (AX-MX-34-120V), and a 200 to 240 V analyzer uses the 240 V lamp (AX-MX-34-240V). Leave the I/II switch on the rear as set.
4. Power and ground: with the power switch off, connect the power cord to a grounded outlet.
5. Fit the pan parts: line up the guide hole of the breeze break ring with the guide on the body, set the pan support so the Δ marks line up, put a sample pan on the pan handle and hook the handle in the notch of the ring. A disposable foil pan goes on top of a sample pan, never on its own.
6. Set the clock: hold SELECT until Cl adj appears, press ENTER, set the date (ymd, mdy or dmy) and time with SELECT, the arrow keys and ENTER, then press RESET to return to weighing. The clock date goes on every GLP and GMP printout.

Analysis modes and ACCURACY

Each measurement program has an analysis mode, a heating pattern and a drying temperature. In standard and quick mode you pick ACCURACY (HI, MID. or LO), and the MX-50 sets the target sample size and the drying rate at which the test ends. The values below are for the factory 0.01 percent display.

Mode (display)	How the test ends	MX-50 settings
Standard (5td)	When the drying rate falls to the value set by ACCURACY	HI: 10 g sample, ends at 0.02 percent per minute. MID.: 5 g, 0.05. LO: 1 g, 0.10. Standard, ramp or step drying.
Quick (quc)	Same, after about 3 minutes at 200 °C	HI: 5 g, 0.05 percent per minute. MID.: 2 g, 0.10. LO: 1 g, 0.20. Quick drying only.
Automatic (U-a)	When the drying rate falls below your preset value	Factory value 0.05 percent per minute. Standard, ramp or step drying.
Timer (U-t)	After a preset time	1 to 480 minutes (1-minute steps to 60, then 5-minute steps); factory value 10 minutes.
Manual (U-m)	When you press STOP	Up to 480 minutes.

Ramp drying raises the temperature gently over a set time; step drying uses two temperature stages; quick drying heats to 200 °C for about 3 minutes and then holds your drying temperature. For safety, the MX-50 limits the temperature to 160 °C once a test has run for an hour, and at 200 °C the lamp thermostat may cut in after about 30 minutes, so let the lamp cool before the next test.

Running a test: MX-50 standard mode step by step

1. Turn the analyzer on; the gram display (0.000g) appears.
2. Press SELECT and use the arrow keys to choose 5td (standard mode).
3. Press SELECT to pick ACCURACY (HI, MID. or LO blinks) and set it with the arrow keys.
4. Press SELECT to pick the drying temperature and set it with the arrow keys (A&D’s example is 130 °C). Press ENTER to store the settings.
5. Fit the breeze break ring, pan support, pan handle and an empty sample pan, close the heater cover, and press RESET when the reading is stable to show zero.
6. Open the cover and spread the sample evenly on the pan, using the level indicator as a guide. The sample mark lights at 0.1 g or more; the MX-50 will not start below 0.1 g.
7. Close the cover and press START once the weight is stable. The display shows the moisture content, the pan temperature, the analysis time and the drying rate in percent per minute.
8. When the drying rate reaches the end value, the buzzer sounds. Lift the pan out with the pan handle, then press ENTER to print the result, or SELECT or RESET to go back to weighing.

Getting accurate results

• Pre-heat first: run a test with an empty sample pan so the analyzer reaches equilibrium. The first result of a series run from cold differs from the rest.
• Use enough sample. A&D’s minimums: at least 2 g if you expect about 1 percent moisture, 5 g at 0.5 percent and 20 g at 0.1 percent. Keep the sample size the same between repeat tests.
• Load samples on a pan that has cooled to room temperature; a hot pan drives off moisture before the test starts. Several pans in rotation speed this up. Do not stack pans.
• Grind grain to a fine, even powder and spread every sample in a thin, even layer.
• For liquids, pastes and samples that melt or form a skin (milk, ketchup, resin, hand soap, caramel), put the sample on or in a glass fiber sheet (AX-MX-32-2). For samples that scorch (high sugar, protein or oil, coffee, peanuts), cover them with a sheet.
• Samples with other volatiles lose more than water as they dry, which reads as extra moisture.

Storing methods in the 20 program numbers

The MX-50 keeps 20 measurement programs, PROG 1 to PROG 20, all set to standard mode and standard drying at the factory. To store one, hold PROGRAM at the gram display, pick a number with the arrow keys, press ENTER, press SELECT to edit the mode, temperature, end value, unit and display resolution, and press ENTER to store. To recall a program, hold PROGRAM, pick the number and press ENTER. When the data memory is on, the display shows MEM and the result count in place of PROG.

Result units: wet basis, dry basis and solids

Unit	Formula (W = wet mass, D = dried mass)
Moisture content, wet basis (factory setting)	(W – D) / W x 100
Moisture content, dry basis (atro)	(W – D) / D x 100
Dry content (solids)	D / W x 100
Ratio	W / D x 100 (the test stops if it reaches 999)
Grams	Sample weight

Checking the MX-50: self-check and the test sample

Self-check

At the gram display, hold PROGRAM until CH appears. Fit the pan parts with an empty sample pan, close the heater cover and press ENTER. The check turns the heater on, tests the temperature sensor and takes about a minute. CH pa55 and a beep mean it passed; an error code means it did not (see the error table below). Clo5e means the heater cover is open.

Sodium tartrate dihydrate test sample

Sodium tartrate dihydrate holds 15.66 percent water in theory, and the MX-50 should read 15.0 to 16.0 percent on it. Set standard mode, standard drying, 160 °C and ACCURACY MID. (about 5 g), pre-heat with an empty pan, press RESET, spread the sample evenly and press START. The result normally comes up in about 8 minutes. Each portion is used once. Replacement test samples are A&D AX-MX-33 (30 g x 12).

MX-50 calibration: weighing sensor and drying temperature

Moisture is a ratio of wet to dry weight, so the weighing calibration does not change the moisture math. A&D still calls for it whenever you need traceable weights for GLP or GMP records, and both calibrations print a report with the model, serial number, ID number, date and time. Our calibration interval guide covers how often to check.

Calibrating the weighing sensor (20 g mass)

1. Warm the analyzer up, then fit the pan, pan support and pan handle and close the heater cover. Keep the bench free of vibration and drafts.
2. At the gram display, hold PROGRAM until CH appears, press SELECT to show Cal and press ENTER to show Cal 0.
3. With a 20 g mass, press ENTER. With a 50 g mass, press SELECT, choose 50.000g with the arrow keys and press ENTER; end and Cal 0 appear.
4. At Cal 0, with the pan empty, press ENTER. The mass value (20) appears.
5. Open the cover, set the mass in the center of the pan and press ENTER. When end appears, remove the mass. If the GLP report is turned on, glp shows while it prints.

A&D recommends a 20 g mass (AX-MX-41, OIML class F1, or AD-1603-20F1) because there is only 26 mm between the pan and the glass housing; a tall 50 g mass needs the housing open. Cal e means the mass read too heavy (something touching the pan or housing, or the wrong value) and -Cal e means it read too light. See calibration weights and weight classes to choose a mass.

Calibrating the drying temperature (AX-MX-43)

1. Replace the weighing pan with the sensor pan of the AX-MX-43 temperature calibrator (listed as AX-43 on A&D’s MX-50 page). Level it with no gap to the pan support, and bend the sensor wire so it clears the heater cover and glass housing.
2. Turn the analyzer on, hold PROGRAM, press SELECT until t-Cal appears and press ENTER.
3. Press START for the 100 °C point. After 15 minutes the buzzer sounds and 100°C blinks; set the blinking value to the thermometer reading with the arrow keys (A&D’s example is 97 °C) and press ENTER.
4. The 160 °C point starts. After another 15 minutes, set the thermometer reading (example 162 °C) and press ENTER to store it and return to weighing.

t-Up means no key was pressed for five minutes and the calibration stopped. Opening the heater cover or pressing STOP also ends it. The MX-50 and MS-70 accept this calibration; the MF-50 and ML-50 do not.

Connecting the MX-50 to a printer or computer

The RS-232C port runs at 2400 bps, 7 data bits, even parity, 1 stop bit, ASCII, with a CR LF terminator. The analyzer is DCE, so it takes a straight-through cable; the included 2 m cable has a 25-pin male plug on the analyzer side and a 9-pin female plug on the computer side. WinCT-Moisture graphs moisture in real time and has an optimum temperature search; A&D’s free WinCT software sends data to a computer. For a computer without a serial port, A&D lists the AD-8527 Quick USB adapter and the AX-USB-25P-EX USB converter; our USB vs RS-232 guide explains the difference. The AD-8127 multi printer prints results, statistics and drying-rate graphs.

Command	What it does
Q	Sends the current data
SIR / C	Starts / stops continuous output
QM	Sends data during a test
START, STOP, RESET, ENTER, SELECT, UP, DOWN, PROGRAM	Same as the key of that name

Function table and data memory

Hold SELECT at the gram display to open the function table. Step through items with SELECT, enter one with ENTER, change it with the arrow keys and store with ENTER; RESET backs out.

Item	Settings (factory setting first)
Cl adj	Clock and calendar
dp	0 dot, 1 comma as the decimal point
prt	0 key mode (ENTER sends data), 1 auto print after each test, 2 stream during the test
data	0 memory off, 1 store every result (up to 100)
5-d	0 moisture only, 1 moisture plus temperature
pU5e	1 about 2 seconds between lines, 0 continuous
info	0 off, 1 full GLP/GMP printout, 2 selected items
id	7-character ID number for calibration reports
Clr	Resets programs, stored results, function table, ID and date order to factory settings

To send every stored result, hold ENTER until out appears, press ENTER, choose out go with the arrow keys and press ENTER. To clear the memory, hold ENTER, press SELECT to show Clr, press ENTER and choose Clr go. fUl means all 100 places are used. Pressing STOP during a test (other than manual mode) means that result is not stored.

Maintenance: cleaning and replacing the halogen lamp

• Turn the analyzer off, unplug it and let every part cool before cleaning. The pan support, sample pan and breeze break ring lift out.
• Clean with a lint-free cloth dampened with warm water and mild detergent. Do not use organic solvents.
• Clean the glass housing when it clouds over; it comes off with two screws. Keep fingerprints off the halogen lamp, and do not touch the metal reflector or the temperature sensor beside the lamp, which can cause drying temperature errors.
• Replace the lamp when drying takes too long, the lamp fails, or it passes its rated life of about 5000 hours. Use AX-MX-34-120V or AX-MX-34-240V to match the voltage label, check the lamp is cool, remove the two glass housing screws, fit the new lamp with its projection facing down, hook the lamp wire and refit the housing without pinching the wire.
• See our scale maintenance guide for a routine check list.

MX-50 error messages

Display	Meaning and fix
CH no	Internal error found by the self-check; call us for repair
Cl pf	Clock battery error; press any key and set the date and time
Cl err	Clock error; needs repair
Clo5e	Heater cover open at the start of the self-check; close it
error0	Internal error; turn the power off and on and check the supply frequency; repair if it stays
error3, error8, error9	IC error; needs repair
Ht err	Temperature control error; turn the power off for more than half an hour and recheck; repair if it stays
t-Up	No key pressed for five minutes during temperature calibration
e	Over capacity; if it shows with an empty pan, needs repair
-e	Too light or pan error; check the pan and pan support, press RESET, calibrate the weighing sensor
Cal e / -Cal e	Calibration mass too heavy / too light; check nothing touches the pan or housing and the mass value is right
fUl	Data memory full; clear it

If the lamp does not light or takes too long to heat: it needs about six seconds to light after START, it gets no power with the cover open or after an overheat until it cools, and a test at a lower temperature cannot start while the lamp is hotter than the set point. Check the lamp voltage against the label and check both fuses with the cord unplugged. Our error code guide covers other A&D messages.

How the MX-50 compares with the rest of the manual

The same manual covers the MS-70 (71 g x 0.0001 g, 30 to 200 °C, temperature calibration), the MF-50 (0.002 g, 10 programs, 50 results, no temperature calibration, RS-232C cable sold separately) and the ML-50 (standard and quick drying only, 5 programs, 30 results). For a side-by-side buying comparison, see our moisture analyzer buying guide.

Setup tips from our technicians

• Write each product’s method into its own program number, so every shift runs the same temperature, end value and sample size.
• Run the sodium tartrate test after a move, a lamp change or a temperature calibration before you trust the next batch.
• Keep a short 20 g mass with the analyzer; it clears the glass housing without opening it.
• Set the ID number and clock first so every calibration printout identifies the instrument.

Common mistakes we see

• Skipping the empty-pan pre-heat and comparing the first cold result with later ones.
• Loading a fresh sample on a hot pan straight out of the last test.
• Running a 1 g sample on a material with well under 1 percent moisture.
• Fitting a 240 V lamp in a 120 V analyzer, or the reverse.
• Wiping the glass housing with solvent or touching the reflector and temperature sensor.

Calibration, repair and rentals from MNM Scales

• Book calibration: the 51 g MX-50 is in our small scale and balance 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. For the drying temperature, call us about the A&D temperature calibrator.
• Mail-in calibration: let the analyzer cool, pack it in its original box and foam, and ship it 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 instrument. Our TDA-registered technicians calibrate lab balances and analyzers at QC labs, plants and warehouses across the Houston area.
• Repair: heater, lamp, display and weighing 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 A&D MX-50 manual?

A&D publishes the MS-70/MX-50/MF-50/ML-50 instruction manual as a PDF, and it is listed under Documents on A&D’s MX-50 page. This guide collects the MX-50 numbers from it.

How do I calibrate the A&D MX-50?

For the weighing sensor, hold PROGRAM until CH appears, press SELECT to Cal and press ENTER. At Cal 0 press ENTER with the pan empty, set the 20 g mass on the pan and press ENTER. When end appears, remove the mass. The drying temperature is calibrated separately with the AX-MX-43 temperature calibrator at 100 and 160 °C.

What weight do I need to calibrate the MX-50?

A 20 g or 50 g mass. A&D recommends 20 g (AX-MX-41, OIML class F1, or AD-1603-20F1) because there is only 26 mm between the pan and the glass housing.

How do I check that my MX-50 reads correctly?

Run the self-check (hold PROGRAM, CH, ENTER; CH pa55 is a pass), then test about 5 g of sodium tartrate dihydrate in standard mode, MID., standard drying at 160 °C. A reading of 15.0 to 16.0 percent means it works properly.

What temperature range does the MX-50 cover?

50 to 200 °C in 1 °C steps. Once a test has run for an hour, the MX-50 limits the temperature to 160 °C for safety.

How many programs and results does the MX-50 store?

20 measurement programs (PROG 1 to 20) and 100 results in the data memory.

How long does the MX-50 halogen lamp last?

About 5000 hours. Replace it with AX-MX-34-120V or AX-MX-34-240V to match the voltage label on the back of the heater cover.

Can the MX-50 connect to a computer?

Yes. It has RS-232C (2400 bps, 7 data bits, even parity, 1 stop bit) and comes with a 2 m cable and WinCT-Moisture software. For USB, A&D lists the AD-8527 Quick USB adapter and the AX-USB-25P-EX converter.