Mass Comparator vs Analytical Balance: How A&D MC Models Compare Test Weights
Mass comparator vs analytical balance: a mass comparator checks a test weight against a reference at one more digit than a standard balance of the same capacity, and the A&D MC-1104AS (1100 g x 0.1 mg) calibrates weights up to 1 kg for $4,499.00, in stock.
Reviewed by MNM Scales technicians · Updated November 2, 2026 · Prices checked November 2, 2026
Short answer: a mass comparator is a balance built to compare a test weight against a reference weight of the same nominal value. It pairs a large capacity with one more digit of resolution than a standard balance of that capacity, so it can check a 500 g or 1 kg weight at 0.1 mg. An analytical balance reads 0.1 mg too, but on loads up to about 220 g to 520 g, and it is built for weighing samples. To calibrate weights up to 1 kg, look at the A&D MC-1104AS ($4,499); for weights up to 5 kg, the A&D MC-6203AS ($7,795). MNM Scales is an authorized A&D Weighing dealer.
This guide is for calibration labs, metrology and QA teams who check their own reference and working weights, and for anyone deciding between a comparator and a lab balance. MNM Scales has sold, calibrated and repaired scales and balances for over 30 years from our shop in Cypress, Texas, and we stock the A&D MC comparators shown here.
What a mass comparator does
A mass comparator measures the difference between two weights rather than the full mass of one. You load the reference weight (A), then the test weight (B), then the reference weight again, at the same timed intervals. A&D calls this the ABA cycle. Averaging the two A readings cancels the balance drift, and the difference to B is the correction for the test weight. An ABBA cycle reads the test weight twice for the same reason. The reference weight should be one class higher than the test weight; our guide to calibration weight classes covers the class limits.
Because only the difference matters, a comparator is tuned for repeatability and resolution at its full capacity. A&D designs its MC comparators to show one more digit than a standard balance of the same capacity. That extra digit also suits work where a small change rides on a heavy tare, such as tracking wear or fill on a heavy part.
Mass comparator vs analytical balance: the specs side by side
| Spec (A&D) | MC-1104A / MC-1104AS comparator | BM-200 analytical balance | BM-500 analytical balance |
|---|---|---|---|
| Capacity | 1100 g | 220 g | 520 g |
| Readability | 0.1 mg (0.0001 g) | 0.1 mg | 0.1 mg |
| Repeatability (standard deviation) | 0.35 mg | 0.1 mg | 0.2 mg |
| Linearity | ±3 mg | ±0.2 mg | ±0.5 mg |
| Pan | 128 x 128 mm | 90 mm round | 90 mm round |
| Built for | Comparing weights up to 1 kg; small changes on heavy loads | Sample weighing, with a built-in ionizer | Sample weighing, with a built-in ionizer |
| Price at MNM Scales | $4,499 | $3,376 | $4,517 |
Read the table this way. On a 200 g load, the BM-200 analytical balance repeats to 0.1 mg, and A&D notes its 0.1 mg analytical balances typically repeat to 1 to 2 digits. The MC-1104A keeps the same 0.1 mg readability up to 1100 g, five times the capacity of a 220 g balance, which is what lets a lab compare 500 g and 1 kg weights at 0.1 mg. So the analytical balance is the tighter tool for samples and small weights, and the comparator is the tool for heavier weights at fine resolution. For how analytical balances differ from each other, see microbalance vs semi-micro vs analytical balance and analytical vs precision balance.
How to size a mass comparator: repeatability, not just readability
A&D’s guidance is to pick a comparator whose repeatability is no more than one sixth of the maximum permissible error of the weight you are calibrating. A&D notes this is industry practice and that one third is often enough, depending on the level your lab manages to. Start from the largest weight you calibrate and its class, look up its permissible error, and compare it with the repeatability in the table below.
- Weights up to 1 kg at 0.1 mg: MC-1104A or MC-1104AS (repeatability 0.35 mg).
- Weights up to about 5 kg at 1 mg: MC-6203AS (repeatability 1.5 mg up to 2 kg, 3.5 mg above 2 kg).
- Heavy weights of 20 kg to 50 kg at 0.1 g: MC-100KS, 101 kg capacity (repeatability 0.1 g at 60 kg, 0.2 g at 100 kg).
A&D MC mass comparators in stock
| Model | Capacity x readability | Repeatability | Linearity | Price |
|---|---|---|---|---|
| A&D MC-1104AS | 1100 g x 0.1 mg | 0.35 mg | ±3 mg | $4,499 |
| A&D MC-1104A | 1100 g x 0.1 mg | 0.35 mg | ±3 mg | $4,499 |
| A&D MC-6203AS | 6200 g x 1 mg | 1.5 mg to 2 kg; 3.5 mg above | ±30 mg | $7,795 |
| A&D MC-6100S | 6100 g x 1 mg | 1.5 mg at 2 kg; 4 mg at 5 kg | ±30 mg | $4,788 |
| A&D MC-100KS | 101 kg x 0.1 g | 0.1 g at 60 kg; 0.2 g at 100 kg | ±2 g | $6,479 |
- MC-1104A and MC-1104AS: A&D’s current 1100 g comparators from the MC-A series, which A&D introduced as the upgraded generation of its MC line. They replace the A&D MC-1000, at the same 1100 g x 0.1 mg, with tighter repeatability (0.35 mg vs 0.5 mg) and a standard USB port.
- MC-6203AS: the 6200 g MC-A model. It replaces the A&D MC-6100S, with the same 165 x 165 mm pan, 1 mg readability and ±30 mg linearity, plus 100 g more capacity, USB and ISD impact shock detection. Our listing ships it with the auto-centering pan.
- MC-100KS: the 101 kg comparator from A&D’s earlier MC series, with an auto-centering 386 x 346 mm pan, internal calibration and the indicator on a 3 m cable, for 20 kg to 50 kg weights.
- Accessories (not included): reference weights; the AD-8922A remote controller and AD-1676 tabletop breeze break for the MC-A series; and for the MC-1104A and MC-1104AS, the AX-MC1104APAN auto-centering pan, which A&D strongly recommends when you load weights by hand.
Last MC-6100S in stock: we have one A&D MC-6100S at $4,788. A&D now builds the MC-6203AS in its place, at $7,795.
Setting up a comparator for weight calibration
- Set the comparator on a solid, level bench away from drafts, vents and sunlight; comparators are more sensitive to the room than a general balance.
- Use A&D’s settings for mass comparison: COND = 2 (slow response), FIL = 1 (stabilization filter on) and TRC = 0 (zero tracking off).
- Plug in and let it warm up for 24 hours with a weight near capacity, or the test weight, on the pan.
- Let reference and test weights reach room temperature; A&D suggests leaving them in the lab from the day before.
- Handle weights with gloves and tweezers or a weight fork, and preload the comparator a few times before the first reading.
- Run ABA or ABBA cycles with a fixed read time, and record each difference.
Rules: weight records and Texas trade scales
A comparator is a lab instrument for calibrating weights, so the rules that matter are your own quality system’s: the reference weights’ certificates, the calibration interval, and records of each comparison. Keep reference weight certificates on file and send the comparator itself for calibration on the schedule your system sets. The weights you calibrate often go on to check trade scales, and a scale used in trade in Texas has to be legal for trade. 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. Our TDA-registered technicians can place trade scales in service. See our NTEP guide and TDA scale certification guide.
Calibration and rental
- BM-200 and BM-500 (0.1 mg analytical balances): in-house calibration with a certificate ($95) or NIST calibration with a NIST-traceable certificate ($395).
- MC-1104A and MC-1104AS (mass comparators): Get a Quote for in-house or NIST-traceable calibration with the brand, model and capacity.
- MC-6203AS and MC-6100S (mass comparators): Get a Quote for in-house or NIST-traceable calibration with the brand, model and capacity.
- MC-100KS: call (832) 290-3120 for a calibration quote.
- On-site service: $295 + $2 per mile per visit across the Houston area, with calibration charged per balance; see on-site calibration in Houston and balance calibration in Houston.
- Certificates: see NIST vs in-house certificates.
- Mail-in, repairs and rentals: send a balance for mail-in calibration, have us repair all brands and types of scales, and rent all types of scales.
Not sure which comparator fits? Send the nominal values and classes of the weights you calibrate, how many you check a year, and whether you load by hand. We will match an A&D model and quote it with calibration. Shop: 21249 FM 529 Rd, Cypress, TX 77433, visits by appointment.
Frequently asked questions
What is a mass comparator?
A balance built to compare a test weight with a reference weight of the same nominal value. It combines a large capacity with one more digit than a standard balance of that capacity.
What is the difference between a mass comparator and an analytical balance?
Both can read 0.1 mg. An analytical balance does it on loads up to about 220 g to 520 g for sample weighing. A comparator such as the A&D MC-1104AS does it up to 1100 g for comparing weights.
Can I calibrate weights on an analytical balance?
Yes, for small weights within its capacity, if its repeatability is no more than one sixth, or for many labs one third, of the weight’s maximum permissible error. Heavier weights need a comparator.
Which A&D mass comparator replaces the MC-6100S?
The A&D MC-6203AS, with the same 165 x 165 mm pan and 1 mg readability, 6200 g capacity, and 1.5 mg repeatability up to 2 kg.
Which A&D mass comparator replaces the MC-1000?
The A&D MC-1104A and MC-1104AS, at the same 1100 g x 0.1 mg, with 0.35 mg repeatability and a standard USB port.
What is the ABA method?
Load the reference weight, then the test weight, then the reference weight again at fixed intervals. Averaging the two reference readings cancels drift, and the difference gives the test weight’s correction.
Can MNM Scales calibrate my comparator or balance?
Yes. We calibrate A&D comparators and balances in-house with a certificate or a NIST-traceable certificate, by mail-in, or on-site across Greater Houston for $295 + $2 per mile per visit.